So far I have only used premium in my 88, but with the gas prices the way they are, I am tempted to try regular unleaded. Am I wasting money? What is everyones opinion on the grade of gasoline I should be using?

BTW, My vette has 49K and runs very strong on the Super Unleaded. I also use Mobil One Oil. Opinion on oil?

 

When I first bought my vette I used regular cause thats what I run in all my vehicles. I noticed it was hesitating off the line and I was told here on the forum to use prem then after about 2 tanks of Chevron prem the hesitation went away.

 

91 is the fuel antiknock index for C4 Corvettes, so I wouldn't use anything less than that.

 

For your l98 which has a lower compression ratio it's ok to run the mid grade/89 octane bu the lt1's DO need the 93 octane.

 

Although running reg/mid will be fine in the short term, premium usually has better detergent qualities that can help keep the fuel system cleaner longer.

I always worry when I fill up on mid grade. I wonder just how many people buy that stuff and how old the stuff in the tanks might be.

 

Higher octane means lower cylinder temps, therefore less power and less chance of keeping the combustion chamber free of carbon.
Use an octane that keeps it from knocking and pinging when getting on it. Unless you have a high compression engine you could be pi$$ing money away.

 

Sunoco, if they still do, uses the pumps to blend their octanes not seperate tanks.

 

some excellent points.i agree with you dont want to run any higher octane than you need to.start with lower octane and see if you have any timing events.if theres no timing being pulled due to the knock sensor activity your fine.
BUT,nowdays there seems to be a problem with cleaners in the gas.specifically no detergents in regular gas.
ive been seeing this in new gms at work.fuel gauges sticking and working erratic.
ive fixed em by adding napa fuel system cleaner and also by putting a tank of supreme in.
for the fleet we decided it cheapest to stock a couple cases of cleaner and add it to any problem rigs.
this is strictly based on tesoro fuel.
in my 92 lt1 i run the mid grade chevron and it seems fine.have ran it in several types of weather with a monitor on it and found no ping.
im at sea level and generaly cool weather though.
theres a gm tsb out not to long ago which listed "approved" brands and type of fuel based on its detergent additives and tesoro was not on the list.gm even had to scramble to produce new fuel gage senders to combat warranties due to this issue.
if you run regular,run some cleaner with it.better yet,go with mid grade.
at least thats how it seems here.

 

Since Shell came out with their V Power that is all I used in my baby. I use it beacuse of the degergent qualities. I will be honest however and mention that I have not since an improvement in mileage but throttle reponse and take off from the line has improved greatly. There is absolutely zero hesitation in my L-98.

Since buying her the first week of August this year I have also ONLY used Mobil-1. The previous owners had only used Dino oil and after the first oil change I can really see a difference in the oil color when I change it. At 3000 miles it is still clear and not black like that Dino stuff

Just my $.02 here
Bob

 

Exactly right

 

OK!

 

Use what your owners manual recomends. Mine says for my '87 that it's ok to run regular, and something about a slight reduction in performance if you do. I tried all grades of fuel and could feel no difference. The octane number is just a reference to the fuels' resistance to burn. IMO, no ping, no problem.

 

I think GM bumped the CR from 9.0 to 9.5:1 with aluminum heads. So that might necessitate the use of 89 octane over 87. I seriously doubt you need or want 91 octane in there though. A new chevy pickup has 9.5:1 CR, and aluminum heads, and I'd bet you'd only put 87 in that. (Although there are many more factors effecting octane requirements, such as heat dissipation, VE, EGR, and spark timing)

Gas with an excessive octane rating will run cooler, weaker, use more gas, and cost you more money. And probably result in more carbon buildup. Of course, we're talking on a marginal scale here. Point is, you won't see a performance gain, only a lighter wallet.

Higher octane fuel isn't better fuel, it's different fuel. Do a little research on how octane levels effect fuel burn, and you'll see that the majority of L98 owners are wasting their money.

I used 91 octane when I first bought my '85. I was one of those "only the best for my baby" type people. Now I'm a little more informed, and I use 87 octane.

 

been running 89 in my LT1 for over a year now and no knocking or pinging...actually gets better gas mileage than if i run 91

 

87 for my 86!

 

93 for my 94- even ran it in my 84...I noticed A LOT of pinging and hesitation in the 84 with 87??? and that was a CROSSFIRE!

With 10.5:1 comp ratio in the LT1- I wouldn't even consider anything less then 93...it even says USE HIGH GRADE FUEL on the gas door...so thats what she get's, what makes her happy...makes me happy!

I look at it like this, they are performance cars- you should ONLY run high grade and high quality products to get maximum efficency...I have seen many a bad or dirty fuel injector from low grade fuels...

Cheers!

 

I have an '88 L98 that I usually use 89 octane. I've experienced no problems such as hesitation, pinging or anything else. I do occasionally run a tank of high quality 93 octane (Sunoco or others) thru it just because of their detergent qualities.

 

Tried a tankfull of mid-grade Amoco 89 oct. in my 93 and saw no difference in performance.Actualy seemed to reduce some of the rich running odor on cold start.

 

Not to get on anyone here but I am always hearing people talk about this. And they are always saying that they want to run the cheap feul because the gas prices are to high. How many miles a day are you putting on your Vette? I mean come on now, the gas here right now where I live is $1.65 for the cheap stuff and like $1.90 -$2 for the good stuff. So going by that to fill my Vette with the cheap crap that I feel tends to plug thing up is going to be $33.00 for a tank. and for the good stuff that the General says to run and should be used in a motor with 10.5/1 compression is $39.00. That's a difference of $6.00 a tank. IHO, if $6.00 a tank is braking the bank you need to look at where your money is really going. I would rather have to skip a meal once a week to pay for the better gas then to put the dirty gas thru my baby. But hey that's just me. <flame suit on>

 

I only use what it says in the owners manual. I figure the engineers at GM know more about this stuf than I do, besides they get paid for it.


I use Shell V-Power 93 octane in mine as that's what it says on the filler door. Use premium fuel only.



It's only driven on nice days, so I figure I can buy the good stuff.