Chevrolet Cruze Forums banner
1 - 18 of 18 Posts

·
Premium Member
Joined
·
4,651 Posts
XtremeRevolution said:
A. Tire pressure/Tires.
XtremeRevolution said:

…A lower tire pressure will soften the ride and provide better dry traction, but will cause more heat due to rolling resistance and reduce fuel economy. Too low of a tire pressure can result in catastrophic failure. A higher tire pressure will stiffen the ride and may compromise dry traction, but will improve fuel economy as much as 3-4mpg.


As your subsequent post clarified, increasing tire pressure has little/no effect on braking distances on various surfaces. What is not mentioned, however, is loss of traction on rough surfaces. Running tires at significantly increased pressures from the manufacturer recommendations increases the amount of rebound a tire has when impacting a bump in the road, which reduces the suspension’s ability to keep the tire in contact with the road not only during braking, but cornering and accelerating as well. People who regularly drive on rough pavement or on gravel/dirt roads may wish to stay closer to the recommended pressures than those who typically drive on better surfaces.

My ’12 Eco recommends 35 psi on all four tires. My personal preference has been to leave the rears set to 35 and increase the fronts to 38 psi since the car carries more weight on the front tires, evening things out a little. I tried increasing all tires to 44 psi, but the increased ride harshness was not worth it (for me on my local roads, anyway).

Another thing to note about tire pressures: the rolling resistance of a tire will increase exponentially as the inflation pressure drops. What this means is, rolling resistance will decrease less and less the more you inflate the tire. Specifically, the difference in rolling resistance will be much greater going from 25-30 psi than it will going from 35-40 psi. The main take-away point here is that making sure your tires are not under-inflated is FAR more important than over inflating them. I personally look at over inflation by a few psi as a way of making sure tires are always at least at the recommended pressures. Setting them a little high gives some room for deflation between top-ups.


XtremeRevolution said:
A. Turn off your heater.

Generally good advice for the reasons you state, but once it gets below freezing you have to get the windshield warmed up above the dewpoint to keep it defrosted.

My tip here is to use the heater on the full windshield defrost setting, but only set the fan to low speed. The more air you pump through the heater core the more heat you pull from the coolant and the longer your engine will take to warm up.

Also note that the AC will not engage when temps are close to or below freezing. Normally the AC comes on when the full windshield defrost setting is chosen on the HVAC control, but in colder temps this is not an issue.


XtremeRevolution said:
B. Watch your RPMs… …I shift into 2nd gear as soon as possible, hit 2000RPM in 2nd, then keep RPMs below 1500 from 3rd through 6th gear. I'm in 5th gear at 35mph and 6th gear at 40mph, cruising at 1100RPM...
RIGHT ON THE MONEY!


XtremeRevolution said:
D. Turn cruise control off. Unless the road is completely flat.

While I agree with most of what you said RE cruise control use, my general advice is to use cruse control as often as possible, unless the terrain is hilly. Kinda the same thing you said, just reversed a bit.

My reasoning for this; it’s almost impossible to manually keep your speed constant, and doing so requires a large percentage of your available concentration. Unless heavy traffic dictates otherwise, using cruise to regulate your speed will generally reduce throttle angle variations (as you constantly speed up and slow down keeping your target speed), keep you from exceeding your desired speed (which uses more fuel), and frees up your mind so you can concentrate on the traffic around you and changing conditions ahead (which saves more fuel than the cruise may waste regulating your speed).

If you’re driving in hilly conditions then, absolutely, do not bother with cruise control. As you stated, anticipating an incline by gently speeding up before it and gradually losing speed while climbing is much more efficient.


XtremeRevolution said:
F. Have a Manual Transmission? Keep the transmission in gear while coasting to a stop. So long as you're above idle, the engine will actually shut off the fuel injectors and allow the transmission to turn the motor over, using zero fuel. While automatics will also do this, you have greater control with the manual. Don't put it in neutral when coming to a stop, leave it in gear until your RPM drops low enough to need to shift out of a gear.
This is both true AND false, and unfortunately for those of you in the US it is not apparent why. Let me explain…

First of all, the Cruze DOES indeed shut off the fuel injectors when coasting… AS LONG AS THE ENGINE IS SPINNING FASTER THAN 1500 RPM WHEN YOU LET OFF THE ACCELERATOR. If the engine is spinning less than 1500 RPM when you back off the accelerator it will keep fueling the engine, which uses more fuel than coasting in neutral with the engine idling. When coasting with the injectors off, the car will turn the injectors back on when RPM drops to 1100 RPM.

How do I know this? I AM CANADIAN. J

Seriously, the fuel economy (consumption in Canada, EH) readout on the DIC is the culprit. When displaying in US units, the highest number the display will read is 99 MPG. This is a LIE when the injectors are turned off during coasting, as the car is effectively getting INFINITE MPG, not 99. Unfortunately, there is no distinguishing between 99 MPG and infinite MPG in the DIC, so you can’t actually see when the injectors turn off and back on again.

When displaying Metric units on the DIC your fuel consumption is displayed in L/100km (idiotic in my opinion, but that’s the way the “powers that be” have made it). The advantage here is that the display WILL read 0.0 L/100km when the injectors shut off, and then resume reporting consumption when they turn back on again. Finally… an advantage to living North of the border! J

What this means is, if you want to save the most fuel possible you need to either:

A: Make sure you’re revving at least 1500 RPM when you let off the gas, or
B: Downshift into a lower gear when coasting to get above 1500 RPM

For hyper-milers that keep their Eco MT’s revving as low as possible, this is good to know. For you US based Eco MT hyper-milers, now you know.

This is a GREAT post, Andrei! Some of the more experienced maxi-milers may debate a few of the finer points and how they apply to different people’s driving scenarios, but as a general read for the average (and un-mileage-educated) driver, this is PURE GOLD. I’m glad to see this is a sticky and I only wish EVERY driver was forced to read and pass a test on this information every time they renew their driver’s licence.

One point of my own I will add to this thread is regarding the most efficient cruising speed. This comes to mind mainly after speaking with a friend of mine who drives a Honda Hybrid and is INTENSELY interested in all things green (he has $30k worth of solar panels on his roof, for example).

This friend of mine made a casual statement that the most efficient speed to drive is 80 km/h (50 MPH). It seems this information is being spread about, regardless of which car you drive.

Generally speaking, the most efficient speed you can drive is:

THE SLOWEST SPEED YOUR CAR CAN COMFORTABLY GO WHILE IN ITS HIGHEST GEAR.

Comfortably in this case meaning able to maintain its speed considering any elevation changes or increased drag due to wind, and usually involves an engine speed around 1000 RPM or slightly above. For a Cruze Eco MT, that speed is going to be between 35-40 MPH.

If anyone wants to try verify this, go to a long flat/level stretch of road with no traffic on a calm day with no wind, and driving back and forth across the same stretch of that road record two-way average fuel economy readings at different speeds. If you want to make it really interesting, try it in different gears also. This will quickly demonstrate why “overdrive” transmissions are popular/necessary, and why the Cruze Eco has THREE overdrive gears.
 

·
Premium Member
Joined
·
4,651 Posts
If the genius that set up the fuel computer had included the ability to display the infinity symbol we wouldn't need to worry about using the metric display!

I generally like the metric system, but expressing fuel "consumption" in litres per 100 km is, in my opinion, extremely stupid and short sighted for one glaring reason: the more efficient our cars get the SMALLER the consumption number gets. This means decreased resolution which is already a problem and we're currently using a decimal place to help!

When I'm driving and using my fuel computer to track my mileage, it takes a long time for the rating to change from, say, 5.0 to 5.1 L/100 km. That's the same as going from 47.0 to 46.1 mpg, which doesn't seem like a lot, but when you're watching your mileage relative to how you're driving it's a pretty big swing compared to 0.1 mpg (roughly 1/9th the resolution).

If the power brains of the metric world had at least done the same sort of thing as the US system and decided to report km/L then I'd be perfectly happy. Instead of 5.0 L/100 km, we'd have a perfectly reasonable 20 km/L... not quite as high a resolution as the mpg system, but at least it would make sense. Not to mention, in 10 years we wouldn't be looking into reporting TWO DECIMAL PLACES just to keep economy ratings from different cars with vastly different consumptions looking relatively the same on the window sticker. Rant over.
 

·
Premium Member
Joined
·
4,651 Posts
I did not realize that the metric readout displays fuel economy in liters/100 km. Not only is this a more sensitive measure, but it also displays fuel economy in the logically correct way... economy of fuel, NOT economy of miles (as in mpg).
Look at my posts on the previous page where I do some calculations of the metric vs. US system. The US MPG system reporting to one decimal place is about 9x more precise than the metric system is reporting to the same one decimal place when talking about consumption values around 5.0L/100km. This means using the US system makes more sense if you're watching how your driving habits influence your average mileage as you drive.

I also include my feelings on the metric system's consumption rating. I don't like it because the numbers are very small to start with and we're using one decimal place to help out. As the consumption of our vehicles gets better and better over time the numbers will continue to get smaller, eventually requiring the use of another decimal point to separate cars with similar looking consumption values (ex. 2.0 vs. 1.9L/100km is the same 5% difference as 40 vs. 42 MPG).

The other thing I don't agree with is the reasoning behind it: PERCEPTION. The US system measures the efficiency of the vehicle (how far it travels on a given amount of fuel), where the metric system measures the consumption of a vehicle (how much fuel it consumes to travel a given distance). What's the difference? What's better? A car that's more efficient, or a car that consumes less fuel? WHO CARES! Tomato - tomaato, six of one or half a dozen of the other? It's the same thing!

To me it just reeks of a "want to be different" for no reason other than the difference itself. An over-paid panel of public servants used a bunch of taxpayer's money to come up with something that has no bearing on anything, and in the end makes for a less user friendly output of data. This is coming from me, a Canadian taxpayer and also a Government employee.

Now, if they had used km/L I would totally understand.

Anyway, let's not derail this thread any more than I already have! Back to improving MILEAGE from our cars! :)
 

·
Premium Member
Joined
·
4,651 Posts
Absolutely not worth the few extra MPG at that price.
It would simplify things a bit if everyone was to start talking in % rather than how many more cents/gallon the premium fuel costs. It's pretty simple (very rough example):

If regular 87 costs $3.00/gal and premium 91 costs $3.30/gal, then premium costs 10% more.

If your mileage increases 10% measured on a tank (ex. 40 - 44 MPG) you are breaking even. If your mileage increases less than 10% (ex. 40 - 43 MPG or less) you are paying more $/mile, and if your mileage increases more than 10% (ex. 40 - 45 MPG or more) you are paying less $/mile.

Somewhere in those value calculations will be any value you place on actual/placebo drivability improvements. Example, if you think your car runs better on premium 91 fuel and the cost per mile is the same as when using regular 87, then you are basically getting better drivability for free. If your car seems to drive better but there isn't enough mileage increase to cover the extra fuel cost then you're paying extra for the added drivability. Whether this is worth it or not will be a personal calculation.

I am halfway through my first tank of 91. After reading so many people claiming benefits in drivability and mileage I had to try it out for myself. I have no comments yet; I will try two full tanks of 91 and then go back to a full tank of 87 before drawing any conclusions.
 

·
Premium Member
Joined
·
4,651 Posts
When you switch back, use two full tanks of 87 for your comparison. I discovered that even though the car starts adapting quickly to change in octane it takes about 500 miles for it to fully adapt.
Probably good advice. The computer stores STFT and LTFT (Short/Long Term Fuel Trim) data. This is basically the short term memory and long term memory for corrections needed from the base fueling tables to keep the air/fuel ratio at the proper level. I'm not sure what this may or may not have to do with the car's sensitivity to fuel octane, but I know the LTFT takes a while to adapt to any changes. I doubt this has any significant relevance but it may, depending on whether A/F ratio is manipulated at all for knock resistance.

To make a short story long... I'll just wait and see. :)
 

·
Premium Member
Joined
·
4,651 Posts
MyShibbyEco said:
I think what blue angel was trying to get at is you can look at this however you want. You can say that Sam uses 85% of the fuel he use to, and Alice uses 75%, so Alice is using less gas relative to the type of car she has. Or you can say Alice went from using 7.84L/100km to 5.88L/100km and Sam went from 19.6L/100km to 16.8L/100km, and Sam is saving more gas per amount of distance.

However, in the end, I think the biggest factor is how much money did you spend in gas to go a certain distance? Sam spent 1071x(cost of gas) where as Alice spent 375x(cost of gas). Alice wins in my book.
VERY WELL PUT, Shibby!

toilet_monkey said:
There is more to it than a simple difference between US and metric units. Some people feel that the American "mpg" and the Canadian/European/rest-of-the-world "L/100km" provide the same data, but they do not actually lead to the same perceptual conclusions.
As I said, the difference is perceptual only. Nobody can convince me that the problem being addressed here does not lie with the owner/driver of the vehicle. Anyone who is interested in reducing their fuel use (for whatever reason) will take the time to understand the (extremely simple) math and how it applies to their situation and the car they are either currently driving or looking to purchase. Most of the car buying public are ignorant of fuel usage, even if they check a box in a survey that says otherwise… sure, they will CLAIM they want to buy a car that uses less fuel, or are interested in ways to improve their driving habits, but this won't stop them from spending more time idling through a drive thru to get a single coffee than it would take them to permanently educate themselves on how to understand their fuel usage.

toilet_monkey said:
Sam and Alice are buying new vehicles. They each drive 15,000 miles per year. Who is saving more gas by getting their new car? Read the following and then decide.

1) Sam's old truck gets 12 mpg. He buys a new truck that gets 14 mpg.
2) Alice's old car gets 30 mpg. She buys a new car that gets 40 mpg.
So in a year Sam saves 179 gallons and Alice only saves 125… so what? This is an absolutely ridiculous argument… it's no different than saying:

1- A large office tower can reduce their electricity use more by shutting the lights off at night than I can by shutting off the main breaker of my circuit panel in my home 24/7.

2- A large factory can reduce their emission of pollutants more by treating/filtering their grey water than a small town can by eliminating toilets.

3- A car company can save more money annually by not painting the inside of their car's ashtrays than I can with a lifetime of not painting anything.

Heck, one of those mega container ships can save more fuel in one trip across the Pacific by scraping the barnacles off the hull than Sam could save in a year by selling his truck, buying a Prius for his truck-driving neighbour, and walking to work!

On an individual basis (and we are all individuals), the good old % method works best. Alice will notice her 25% reduction in fuel costs much more than Sam will notice his 14%.

toilet_monkey said:
Make your choice.
Well by the argument you are supporting, the best option would be for Sam to buy Alice's old car! :) Then he could go from using 1250 gallons to using only 500 gallons, for a savings of 750 gallons… but if you step back from the situation and look at it again, you will see that Sam is still using 33% more fuel than Alice is in her new car. At least in this scenario Sam will notice the difference; he would be saving 53% on his fuel costs.

Reducing the number of gallons consumed by the population is a concern at the Federal level. Unfortunately for the country, individuals (the majority of whom are ignorant of fuel use) are only concerned by how much money is spent on driving, and are unwilling and therefore unable to make better choices when it comes to vehicle purchases and driving habits.

toilet_monkey said:
Most people don't understand how mpg actually relates to fuel consumption--and it's not entirely their fault. After all, mpg seems pretty intuitive. But the problem is that mpg doesn't actually tell us what we want to know: fuel economy. This is why it's better to gauge fuel economy in L/100km instead of mpg. With the metric system method, every vehicle can be easily assessed for how much fuel it actually uses!
The math is so simple that I have absolutely no sympathy for someone who can't figure it out, and by figure it out I mean actually figure it out on their own through their own existing skills, reading up on it, or getting someone to explain it to them. "On a given amount of fuel, car X will go this much farther than car Y." I can't imagine that expressing it the opposite way using Gal/mi would make any difference at all in the average person's ability to comprehend fuel use.

toilet_monkey said:
As cars become more efficient, the engineers will just add another level of magnitude to the denominator. Instead of L/100km, it will be L/1000km, or L/10,000km.
Brilliant! Just when everyone will get used to using one method it will change again, requiring the math-inept public to once again seek help or bury their heads in the sand.

toilet_monkey said:
Besides, we won't be using internal combustion engines for much longer anyway (< 40 more years).
That's what we were saying 40 years ago! :)

BTW, I hope I don't come across as an ass… it is the system I'm arguing against, not you. I realise that there are reasons for/against every debatable topic, and a good debate is always a good time!

On this particular topic I have a feeling we are going to have to agree to disagree. I firmly believe that the responsability should be put soley on the driving public. It should not have to be a Government requirement to dumb it down so that ignorant people are able to understand it without understanding it or even caring about it.
 

·
Premium Member
Joined
·
4,651 Posts
Short term in ECU time is usually a couple seconds or less, long term is usually a couple minutes. The car will adjust short and long term trims before you are home from the gas station. The slow changing effect people feel from switching from high octane to low octane (or vise-versa) is more from the gasoline being a mixture of the two different octanes, and it takes a couple tanks of one type to dilute the other enough to make a noticeable impact.
Thanks, I didn't know LTFT updated so quickly! I thought it was more like several hours...
 

·
Premium Member
Joined
·
4,651 Posts
A large percentage of my daily commute is done with the cruise control set at 40-45 MPH. This will keep my average speed very low (suggesting more city driving) compared to someone who's average speed is much higher (suggesting more highway driving), but I'm actually getting significantly better mileage doing 40-45 MPH than someone who is travelling faster on a highway.

Generally speaking your thinking for average speeds may be correct, but it does not apply to someone like me, for sure.
 

·
Premium Member
Joined
·
4,651 Posts
As long as you can do this in 6th gear you should be averaging close to or above 60 MPG on this stretch of your commute.
Yep, on a warm day the DIC is boucing around between 50 and 75 MPG for most of this strech of road, 6th gear all the way with cruise set and reving less than 1500 RPM. It's also fairly level with few elevation changes as it follows the river, definitely a nice drive, by far the nicest commute I've ever had and far nicer than what most people go through.
 

·
Premium Member
Joined
·
4,651 Posts
Blue Angel's DIC is working normally for the ECO MT. My instantaneous MPG swings wildly from high 30s to all the way up to 99 while cruzing at 50-55 MPH on cruze control. At that speed, the car is really sensitive to terrain and wind.
Since ~November I've been using 91 Octane gas and have noticed the mileage readout on the DIC is much more stable. Yes, as the cruise control gently compensates for wind and grade changes the numbers rise and fall, but I found with 87 octane fuel the numbers seemed to bounce around a lot more and for little apparent reason.

My own personal theory on this (after reading several others personal accounts of using higher octane fuel) is that the timing map in this car is VERY agressive and the ECM is constantly advancing timing and then pulling back on the onset of knock. It seems to do this pretty much all the time, even in the lightest of load conditions such as mine: at 40 MPH on level ground with no head wind and the cruise set.

For the record I will be swiching back to 87 octane when the weather warms up and driving conditions become more consistent to try to quantify the difference in fuel octanes (I will also attempt to log the difference with some sort of scanning device). Everyone has different driving environments, so a "one size fits all" solution to the debate may not work. I will post any findings I have that I think may be relevant.
 

·
Premium Member
Joined
·
4,651 Posts
Cruse control is what I missed, personally I never use it.
IMHO a waste of fuel.
My last 25k mi avg of 48mpg.
IMHO, cruise control saves FAR more fuel than it wastes, for most people in most situations that is. If you are the type that is able to ruthlessly focus your attention on maintaining your speed with the least mileage-invasive throttle inputs possible, then you may be able to save some fuel vs. using cruise control. The major exception to this would be for those who are driving in hilly areas where the car is constantly navigating elevation changes. In this situation you are usually best to avoid cruise control and gently accelerate leading up to the hill followed by gradual slowing while climbing the hill, then using gravity to help you back up to speed going down the other side.

For most people driving on most roads where elevation chages are few and far between, or happen over long gradual slopes, using cruise control will save fuel. The reason is most people cannot keep a constant speed while driving and are constantly slowing down and speeding back up. This wastes fuel.

I use cruise control all the time, even in town, as it liberates my concentration for other things like antipating trafic patterns and timing lights at intersections. These things save far more fuel for me and the way I drive then not using cruise control to maintain my speed over relatively level terrain. On the highway, using cruise control liberates my right foot from being chained-to and constantly manipulating the throttle pedal as well as relieving my brain of the constant work of maintaining the same speed for hours at a time. I would not buy a car without cruise control... that and an oil pan heater were the only options I put on this car when I bought it.

Each to their own:)
Exactly! :)
 

·
Premium Member
Joined
·
4,651 Posts
Y'all are crazy with 50+mpg, I can't even hit 30.
Plop your Cruze onto the nearest highway, set the cruise control at the speed limit, reset your mileage calculator and be amazed. 30 will be easy to hit, and you will relise that it is only the amount of "city" style driving that is keeping your mileage low. Well, that and maybe some driver habits that could use correcting. :)

It takes a concentrated effort for me to keep my mileage as high as it is, and the majority of my driving (my daily commute) is relatively easy compared to most regarding mileage. I think it's entertaining, almost like a game, to try to keep the mileage up. The Cruze is not a fast car, so trying to drive it that way gives little reward. It is a very efficient car though, and driving it in that manner IS rewarding, to me anyway.

I have another car that is very efficient at burning lots of gas and is very good at going fast, so it's rewarding to drive it as such. It's a bit of a game in it's own way and makes putting around at over 40 MPG in my Cruze much more "interesting" then it might otherwise be.
 

·
Premium Member
Joined
·
4,651 Posts
Generally speaking, it is good to take advantage of DFCO if you have to slow down or stop anyway, but it's better to coast in neutral down slight grades; the tiny amount of fuel it takes to idle the little 1.4 is more than made up for in extra forward momentum.

If you are already driving above the limit and are flirting with a speeding ticket you won't have any headroom when coasting, but if your speeds are a little lower you can then afford to speed up slightly going down a grade, preserving momentum and coasting for some distance after the hill before your speed returns to normal.

As obermd pointed out, longer and/or steeper grades are a good place to use DFCO since without some sort of braking your speed would get too high, and idling the engine with your foot on the brake doesn't make much sense. Keeping engine revs high enough to keep DFCO engaged (above 1500 RPM) and using the brakes as necessary will be the most efficient way to go.
 

·
Premium Member
Joined
·
4,651 Posts
...bought a 2013 cruze Lt1. getting abissmal fuel economy. 23 mpg city and 34 hwy. daughters cruze eco is getting low to mid 50 mpg. why is this?!
The way they're driven. I'm sure if you traded cars for a week her 50 MPG Eco's mileage would plummet down to near what you're seeing out of your 1LT, and your car's mileage would jump into the 40's. The Eco does get better mileage, no doubt, but the difference isn't +47% (50/34).
 

·
Premium Member
Joined
·
4,651 Posts
I still feel that its a different program in the eco that uses a different fuel map to achieve those economy numbers
If I remember correctly, the boost map is different on the manual transmission cars. The automatic cars are tuned to have full boost by ~1800 RPM while the manuals have the boost delayed, gradually increasing until ~2500 RPM or so. For around town driving this means far less access to boost at low RPM and higher mileage to boot.

BTW, the boyfriend can't be much of a leadfoot if the Eco is averaging 50 MPG (check my sig). I've been averaging almost 50 MPG lately in my Eco and to do that I have to leave the lead feet in the closet and put on the feather slippers. I do a full throttle 2nd gear pull now and then for the sake of science, but other than that I'm hypermiling this thing.
 

·
Premium Member
Joined
·
4,651 Posts
What Rob said.

Early Cruze production were subject to a TSB to install insulation shielding the driver's right leg from the heat of circulating coolant. The lines to the heater core are right behind the trim and the heat was cooking people's legs in the summer even with the AC on.
 

·
Premium Member
Joined
·
4,651 Posts
That said, your driving habits alone are the biggest impact on MPG and $ saved that you'll see at the pump.
Expanding on this a little for everyone's knowledge, my personal experience is that I don't see an increase in mileage with higher octane fuel, but let me explain why...

The harder you drive a car, the more load you put on the engine and the higher the combustion pressures are (more pressure = more torque). Demanding more torque from an engine means it's more likely to knock on lower grade fuel, which means the engine will pull timing to keep the knock in check. When the engine pulls timing it loses efficiency.

This all means that a lead-foot driver that spends most of their time driving in the city constantly accelerating, or doing 80+MPH on the freeway all the time, will gain the most mileage from higher octane fuel.

In my case, I drive easier than your Grandma and my commute is mostly low speeds with the cruise control set. I simply don't load the engine enough that it's running inefficiently even on 87 octane.

My persoanl reason for choosing higher octane fuel is the car runs much smoother, especially at lower engine speeds where I'm constantly lugging the engine up inclines in 6th gear. The extra few bucks on a fill is worth it for the smooth running... $0.16/L on a 40L fill is $6.40. Over the course of a two week tank of fuel, not significant for me anyway.

Part of my brain still believes that I'm getting slightly better fuel economy with higher octane since it allows me to use taller gears and lug the engine down farther, even if the savings are not significant enough to be evident in tank to tank fill up calculations. Since I can't back that up with hard numbers, it's just a hunch.
 

·
Premium Member
Joined
·
4,651 Posts
...by not allowing your vehicle warm up before taking off your doing a lot more damage...
XR made some great points in his post.

I will add that many car companies advise against idling at startup, and indicate the engine will warm up faster under light driving conditions than it will idling. The key there is LIGHT drivng. Placing the engine under high loads and/or high RPM is not recommemded while it is cold since parts have not thermally expanded to the proper fit, which can increase wear. Also, oil has anti-friction additives that don't work at low temperatures.

Avoiding start-up idling (like using remote start):

- has a dramatic impact on your car's efficiency, and that impact is greater as trips get shorter
- reduces cold start wear, as parts expand to proper size/fit sooner
- increases oil life, since the engine "leans-out" sooner and adds less fuel contamination to the oil

As XR said, modern synthetic oils flow very well at all but the most extreme low temperatures; temperatures below what anyone living south of Alaska is ever likely to see. In most modern engines oil has fully circulated and pressure has stabilized within a few seconds of startup. Drive it easy until the coolant gauge starts to move, don't beat on it until it's fully warm (or at all if you want to save gas), and you'll be good to go.
 
1 - 18 of 18 Posts
Top