[obermd]

Question for those of you living in the flat parts of the US. For driving across Kansas, Illinois, and Indiana on I-70 in an ECO MT, what octane would you recommend? Basically I'm going to be sitting on Cruze control for hours on end. Central Missouri is hilly enough that I'll run 91 or higher depending on what's available. Northeast of Columbus, Ohio I'll run 91 or higher to handle the hills of the Appalachian mountains.

 

[jblackburn]

Question for those of you living in the flat parts of the US. For driving across Kansas, Illinois, and Indiana on I-70 in an ECO MT, what octane would you recommend? Basically I'm going to be sitting on Cruze control for hours on end. Central Missouri is hilly enough that I'll run 91 or higher depending on what's available. Northeast of Columbus, Ohio I'll run 91 or higher to handle the hills of the Appalachian mountains.

It does perfectly fine on 89 at lower elevations with no hills. Heck, even with hills, it does fine @ 3000 ft.

Course...depends how hot it is when you make the trip. If it's above 90, I step up to premium. Other than that, gas is over $4 here for premium and I refuse to pay that.

 

[bduffey723]

Question for those of you living in the flat parts of the US. For driving across Kansas, Illinois, and Indiana on I-70 in an ECO MT, what octane would you recommend? Basically I'm going to be sitting on Cruze control for hours on end. Central Missouri is hilly enough that I'll run 91 or higher depending on what's available. Northeast of Columbus, Ohio I'll run 91 or higher to handle the hills of the Appalachian mountains.

Midgrade should be more than fine for that. The heat isn't too bad yet for this area to bump it up to premium. I don't ever recommend regular. Always midgrade at least. Just beware of Illinois drivers. They think the left lane on the highway is for going just the posted speed limit and that's it. Regional tractor drivers from this area feel like lane signalling is not needed as well. Oh, and fill up before crossing the into Illinios. The gas instantly gets higher right over the border.

 

[nebojsa]

I thought that the only difference between the regular and premium is the octane amount, plus the price. The older cars,if you get engine knock you go to premium.
I think that today's cars more/less don't have that knok problem ,but that is me.Regular gas or premium gas, they both have the same amount of heat energy...don't they ?

 

[jblackburn]

Slightly less in premium. Not a huge difference in BTUs. Usually premium contains a higher % ethanol, which helps to reduce knock.


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[spacedout]

I thought that the only difference between the regular and premium is the octane amount, plus the price. The older cars,if you get engine knock you go to premium.
I think that today's cars more/less don't have that knok problem ,but that is me.Regular gas or premium gas, they both have the same amount of heat energy...don't they ?

Depends on if both grades have 10% ethanol. Around me most stations premium is 91 octane no ethanol, so it actually has a few thousand more BTU per gallon.

You are also overlooking the high heat of a turbo engine, in the past ALL turbo engines required premium gas. The only thing that changed is they now are relying on the knock sensor and ECU to hopefully quickly enough adjust ignition timing to prevent engine damage. This means with 87 octane the engine is constantly de-tuning itself so you loose MPG and power.

 

[jblackburn]

Depends on if both grades have 10% ethanol. Around me most stations premium is 91 octane no ethanol, so it actually has a few thousand more BTU per gallon.

Ah...it's UP TO 10%. Regular is more like 5-7%, while premium is 10% in most places.




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[spacedout]

According to the link below summer gas with no ethanol contains 114,500BTU. Ethanol gas contains 111,836. That's 2,664BTU extra energy per gallon running pure gas.

2,664BTU X 15.6gallons(size of my 1LT tank)= 41,558.4BTU extra per tank. That's only equal to less than a 1/2 gallon extra energy.

Gasoline gallon equivalent - Wikipedia, the free encyclopedia

 

[spacedout]

Ah...it's UP TO 10%. Regular is more like 5-7%, while premium is 10% in most places.

Is that what the pumps say where you live? Wisconsin has a strict labeling policy and all grades that contain ethanol say "contains 10% ethanol per gallon". The only questionable wording at the pump is on octane.... if I buy 91octane in fine print is says "91 octane minimum", meaning if could be higher. all grades say something similar.

 

[tecollins1]

93
Ussually Sunoco (since it has a very large market in PA -headquarters in Philly-)

The other popular gas stations are "Sheetz" and "Get Go" (who knows where they get their gas from)

 

[Patman]

strictly 87 because it's cheaper. 13 eco 1.4 auto ran 122 mph by gps with a bit left on 87. i'd say that's good enough dead stock. oh and the manual says 87 or higher, then goes on to talk about knocking. no knocking on 87 here.

I have not found any benefit to anything higher. I am not tuned and the car runs fine with 87. Why waste the money. I wasted enough on my tuned 1.8. The req. use of 93 in the 1.8 was one reason I am glad it is gone!

 

[Robby]

87 winter, 89 summer.

Rob

 

[obermd]

In Denver 85 is "regular" due to altitude. Lower air pressure reduces the chance of engine knock. Until I purchased my ECO MT 85 ran fine in every car I owned. My ECO MT requires 91 for throttle smoothness, especially in the summer. In the winter I can get away with 89 but even in the cooler temperatures I still notice throttle pulsing on 89. Penguin LS also runs noticeably better on 91 octane vs. 85, 87, and 89 octane so it also runs 91 octane.

 

[coastlvr]

I have been using 87 in my 2011 Cruze LTZ, but i am nearly convin ced i will have to use at least 89 & possibly 91 octane to obtain any decent gas mileage.

 

[obermd]

Agree totaly! I know many people say you're wasting your money and that it realy makes no diferance but for me and my Cruze we will use premium!

For most cars you are wasting money running higher octane than needed. Even with the Cruze some of our members have discovered that mid-grade is sufficient so they would be wasting money going to premium.

 

[Rbk_3]

91 because its the only ethanol free I can get here

 

[RedneckCamokid]

Haven't seen those since the 1990's!

Got one in town! Popular little stop, but mostly I go to Circle K for my gas. 91 or 93, depending on where I go.

 

[jandree22]

Bringing this thread back up because I did a little math for my experience. Crunched the numbers from my Fuelly log eliminating the outliers (first fuel up, pure highway trips, etc) to try and get the most accurate picture of my typical commute routine. My sample size is still admittedly small, but when comparing 89 tanks to 92/93 tanks, I found:

92/93 --- 37.47 mpg (15 tanks)
89 --- 37.45 mpg (6 tanks)

Most of the 89 tanks were Feb-March, so on the one hand still on winter blend fuel and cold ambient temps, but on the other hand I wasn’t up against extreme summer heat/AC usage. The basic idea is the mpgs are nearly identical IME so far. Around here most midgrade is only $.10 more than 87, while premium is $.30-.40 more than 87... so the financial end is really tipping towards midgrade. I have been a proponent of using premium but 89 is really, really close in performance and now evidently mpgs as well. Will go back to 89 for a while and see how things pan out in the summer heat.