Chevrolet Cruze Forums banner
41 - 60 of 127 Posts

·
Registered
Joined
·
247 Posts
I'm not an automotive engineer, just a "shade-tree" mechanic type of guy, but my LTZ runs better on 93 vs the 87 (can't find 91 around here). I don't know the reason, and it may be psychological, but the car seems more peppy with the higher octane. Also according to the DIC, I average 34 mpg on the highway with 93 and 30 with the 87 over the same route.
 

·
Registered
Joined
·
644 Posts
here's a question, will the 93 gas last longer?I mean if I usually put 10 gallons for example, will 10 g of 93 last longer than the same 10 g of 87?
 

·
Premium Member
Joined
·
4,339 Posts
here's a question, will the 93 gas last longer?I mean if I usually put 10 gallons for example, will 10 g of 93 last longer than the same 10 g of 87?
...audog has your answer:

I'm not an automotive engineer, just a "shade-tree" mechanic type of guy, but my LTZ runs better on 93 vs the 87 (can't find 91 around here). I don't know the reason, and it may be psychological, but the car seems more peppy with the higher octane. Also according to the DIC, I average 34 mpg on the highway with 93 octane and 30 mpg with the 87 octane over the same route.
 

·
Premium Member
Joined
·
2,704 Posts
Discussion Starter · #44 ·
There is not always a difference in fuel mileage. There is no difference for me. It's mainly a performance and better for your engine type deal. Differences in mileage may be if your switching between different stations and brands, etc. The Sunoco I usually go to gives me the same mileage on 87, 91, and 93 and its been that way with my last vehicle too. But all grades of its gas seem to give me 2-3 mpg better than the no-name (aka big corp.) gas stations in the area.
 

·
Registered
Joined
·
644 Posts
Money wise, I always put $30, it lasts just under a week. So as my first 93 tank, I did $30 to see the difference in how long til I needed to fill up again. I usually get around 8.8x gallons each fill up with 87, I got 8.406 gallons with 93 octane. not bad.
 

·
Registered
Joined
·
644 Posts
Well, I did a little city driving and did notice a difference in performance and smoothness of shifting, I drive manumatic in city. I don't think I went far enough to see any mpg difference.
 

·
Registered
Joined
·
267 Posts
I'm just about to finish my first FULL tank of 91 octane. So far, gas mileage has been about the same (more or less) as with 87. However, I believe i've had a little more stop and go traffic to contend with...so I'm sure my MPG's could have a bit better.

I did notice the car felt better though.
 

·
Registered
Joined
·
644 Posts
So, my car feels better, BUT;
When I filled up yesterday, I was at 3 quarters full of 93, today, after only 100 or so miles, I'm just over a quarter tank, so this stuff obviously is used up much faster, not looking good.
 

·
Premium Member
Joined
·
5,157 Posts
If you don't fill up at the same pump with the same technique every time when tracking fuel mileage, the results are tainted. They're good for rough changes, but not for tracking fine changes like 1-2 mpg difference over a commute.

One also needs about 3 tanks to really discern a change as fine as 1-2 mpg.
 

·
Registered
Joined
·
644 Posts
I already see a small increase in mpg. I rarely use the same pump but always use the same place and I never knew there was a technique. I just put it in and go.
 

·
Registered
Joined
·
178 Posts
Ran 2 tanks each with both 91 and 87 just for trial and I get absolutely NO change in fuel mileage. At all. Slightly smoother performance with Premium, but nothing really to warrant the extra cost. I use Sunoco since its the only decently tiered gasoline near my home. However here in college I have access to both Exxon and Shell and switched to them since they are top tier. Either way, octane rating has caused no difference for me at all. Anyone's thoughts on this?
I don't claim to be any kind of expert but different octane levels won't make a difference in your MPG. If your gas stations are like the ones in my area running premium in your car will get you slightly better MPG because there is no ethanol in the premium vs 10% ethanol in regular.

If I am remembering this correctly awhile back I read an article about E85 (85% ethanol) and it said you would have to burn 1.5 gallons of E85 to get the same energy output of a gallon of gasoline.

My advice is if you are running premium in order to get better MPG I would be figuring out what your cost per mile is for both regular and premium. Ultimately if you are not saving any money then it is not worth it.
 

·
Premium Member
Joined
·
1,693 Posts
I have been using 92 octane from WAWA for months and decided to try 93 from sunoco. Im not sure if its my mind playing tricks on me but the car is running better then ever and so far im averaging 3 mpg higher then before.
 

·
FI Lunatic
Joined
·
1,380 Posts
My salesman only runs Shell (89)
in his vehicles. He didn't realize Shell was top tier, and said he gets about 80 miles more per tank using Shell. I've been trying to find a convenient top tier station to try, but most are out of my way.

Sent from my ADR6400L using AutoGuide App
 

·
Premium Member
Joined
·
1,943 Posts
Well, last weekend I filled mine up with 93 octane for the very first time and now, after 280 miles I honestly say that I can NOT tell any difference in power, smoothness or mpg. So I am going back and staying with 87!
 

·
Registered
Joined
·
644 Posts
my car is still at the dealer, but when I first put 93 I noticed better performance, no mpg as I hardly got to drive it.
 

·
Premium Member
Joined
·
2,134 Posts
Octane rating has zero direct affect on fuel mileage. There is roughly the same amount of energy in 87 octane and 93 octane. The changes come from the fuels ability to resist detonation and the abilities it gives your engine. What the higher octane does is let your car run more advanced timing which in turn gives you more power and efficiency. What you perceive as better economy is a just a better running engine which gives you the driver the ability to make up that fuel mileage. It is more noticeable on high compression and forced induction engines. The Corvette that was referenced here will run on 87 but the computer is going to back out a ton of timing to avoid detonation once it starts to detect knock from the lower octane gas. So yes you can run it on 87 but it kind of defeats the point of having a Corvette when it is down 40+HP. Same thing with our cars. with the higher octane the computer can give you more boost sooner and push the timing ahead which will give you more power. If you don't change your driving habits that increased power will mean the engine will not have to work as hard or accelerate as long to do the same amount of work, and hence up goes the MPG.
 

·
Premium Member
Joined
·
2,704 Posts
Discussion Starter · #58 ·
Kind of a random thought, but I find Sunoco and Shell to be by far the best gas from a fuel mileage standpoint. Despite not being "top tier" Sunoco consistently outperforms Exxon and Mobil in my experience. And shell is just shell, its giving me some 40 MPG on the highway in just an LTZ
 

·
Premium Member
Joined
·
2,134 Posts
^
I agree with him. However, I don't believe with a lower compression NA engine you will see benefits from running premium.
I agree. On a low compression plain jane motor you are pumping away the dollars for no real reason. If the car isn't detecting knock you can run 114 octane and it won't give you an ounce more power unless you change the tune.
 

·
Registered
Joined
·
35 Posts
Quite interesting to know what sort of RON US has. Here in Malaysia our lowest RON is 95 and the premium being RON 98. Price wise is RM 1.8 / L for RON 95 and RM 2.80 / L for RON 98. To convert it is approximately RM 3 to USD 1. So a full tank here is approximately RM 100 which is about USD 30. What are you guys paying over there?
 
41 - 60 of 127 Posts
Top