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Discussion Starter · #1 ·
I have been running Shell 87 octane fuel in my AWD Terrain since the first fill up. Has anyone used Premium in their I4 and if so did you notice an increase in MPGs?

My C5 Corvette (back when it was stock) ran much better with premium. Just wondering if anyone has tried this.
Thanks for the input
Fireman591
 

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I have not used premium and have no intention too. This car calls for 87 octane. Using premium will not yield a noticeable increase in mpg.
 

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well your c5 says to use 91 or better.....

your nox says 87......

running a different octane wont yield you better results....
 

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I used Premium fuel in my I4 back in the summer because it was "pinging" so badly on gentle acceleration. Premium fuel stopped the pinging. Did not notice any significant effect on mileage at all.
With the colder weather, I switched back to "regular" as there was no pinging. There is supposed to be a TSB from GM about this pinging issue...many have experienced it..some are saying it is the fuel pump....but my experience with the pinging, and the fact it is "cured" albeit temporarily by using Premium fuel, confirms my belief that the Terrain I4 is set up so lean and with timing set too advanced to get good gas mileage...and it is good for a heavy vehicle......

However, when the warmer weather arrives back here, if the pinging starts again, my Terrain will be headed to the dealership and we'll see if GM has come up with a fix for this.....
Premium gas up here (N. Ontario) now is $1.31 per litre, or almost 6 bucks a gallon....thats not good!!!!!!!
 

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Discussion Starter · #5 ·
Mrmidnite2 said:
I used Premium fuel in my I4 back in the summer because it was "pinging" so badly on gentle acceleration. Premium fuel stopped the pinging. Did not notice any significant effect on mileage at all.
With the colder weather, I switched back to "regular" as there was no pinging. There is supposed to be a TSB from GM about this pinging issue...many have experienced it..some are saying it is the fuel pump....but my experience with the pinging, and the fact it is "cured" albeit temporarily by using Premium fuel, confirms my belief that the Terrain I4 is set up so lean and with timing set too advanced to get good gas mileage...and it is good for a heavy vehicle......

However, when the warmer weather arrives back here, if the pinging starts again, my Terrain will be headed to the dealership and we'll see if GM has come up with a fix for this.....
Premium gas up here (N. Ontario) now is $1.31 per litre, or almost 6 bucks a gallon....thats not good!!!!!!!
Dang how do I get one of those lean programs installed? Mine is running so rich the oil is full of fuel. I need to get a scanner and get the readings at the O2 sensor before the cat.

Hopefully your dealer will be able to help you out if the pinging starts up again.
 

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Never had a vehicle that ran on premium and never will, not my Harley or my Vettes. Yes you will get the full power output with the premium, but in day to day driving regular is fine.....unless for some reason your engine pings.....then you have no choice.
If GM said the Terrains had to use 91 octane, then today I would be driving a Hyundai Tucson.
 

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In the old days with carburated high compression engines you needed premium grade gas. My 66 Pontiac ran 101 octane and once I put in cheap gas and it pinged so bad I had to reset the timing to burn off that tank of fuel At that time premium gas was less than $0.40/gallon. The current crop of cars are computer controlled with knock sensors which shoul automatically adjust the timing for the knock. If it doesn't there is something wrong with the computer which should be adusted by the dealer.
 

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Unless the car calls for it, no need. I used 89 in ours for a month or so and there was no difference in power nor MPG.
 
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