What octane do you guys all use?

I've been noticing in my area the decline in good gas. We used to have 93 at every station. Now theres only 1 or 2 left. Most only carry 91. and now they are starting to add ethanol to those even!

Is ethanol bad for these cars? whats the minimum octane?
The other concern is that with the nitrous, I dont want to be spraying on 87. lol.

 

Our cars were designed to get top performance from 91 octane....that said you can use 89 or even 87 but performance will suffer and highly modded engines may be damaged from detonation.......

Another fact is that the higher the elevation the less octane you need....that is why 91 is "usually" the highest octane you can find in areas that are high elevation..

Most gas in this country contains up to 10% ethanol.......the problem with ethanol is not that it damages your engine rather it is it hurts power and MPG.....ethanol is about politics and costs more than the gas it replaces.....and our current administration is wanting to increase the max to 15% which will only hurt MPG and power..............

On another note ethanol is about 110 octane and some have tuned FI engines to run on 70%+ ethanol (known as E85) with great success....but MPG is terrible..

 

I buy from very few stations. I always get PREMIUM at whatever octane it is.

I think the key is to get fresh fuel, from a place you trust has consistant product at a reasonable price.

 

93 octane is all I use in my vette.

 

my last "fun" weekend car got about 8 mpg. lol I dont mind about mpg. All I care about is making sure my car wont explode. Even if it costs a few horsepower.

And premium from gas station to gas station varies. Certian ones here are 91. (such as BP) and others premium is 93.

 

91 octane since we don't get 93 octane. I would NEVER put 89 or 87 octane in my supercharged corvette.

 

All we have around here is 91.

 

91+ i hate using 91 even. 92 is somewhat common around here and 93 is rare my car is tuned at a 92/93 combo

 

90% of the time i use 87 colored if i'm in the city and don't have much gas i'll put in w/e is the premium is usually 93.

 

Used Chevron 93 untill they left...(bastiches)
now BP Amoco 93 or Exxon 93 and add Techron concentrate all the time.

 

ive seen techron mentioned on here. What does it do?

 

always 93... here every station is 93 for premium... except sunoco, which sells 91 at the same price as everyone else does for 93... then sells their 93 for even MORE... sunoco used to sell 94 in place of the current 93

 

This subject comes up often and always generates a heated debate.

The owners Manual actually says:

“Fuel - Gasoline Octane

Use premium unleaded gasoline with a posted octane of 91 or higher for best performance. You may also use middle grade or regular unleaded gasoline rated at 87 octane or higher, but your vehicle’s acceleration may be slightly reduced. If the octane is less than 87, you may get a heavy knocking noise when you drive. If it is bad enough, it can damage your engine.”

E-T, who was involved in the design of the C5, will post long explanations of why the high compression of the LS1 (the LS1 has 10.1:1 compression ratio and the LS6 10.5:1) needs good gas. His advice is 91 minimum and 93 if you can get it. It has a knock sensor which automatically retards the ignition if it senses knock. If its doing that, by definition you have less power and lower fuel efficiency.

In my book, although the knock sensor may protect the engine to a certain degree, it’s still a compensatory adjustment. In other words it’s solving the problem after the event so some damage could occur however slight.

For a couple of cents a gallon, I wouldn't take the chance. JMHO. If you can't find 93, 91 is fine. I never had any trouble in Vegas even with the higher temperatures but I guess that just proves the knock sensor was working.

In UK Regular gas is 95 octane (RON) which equates to 91 octane in the US. The Super Unleaded is 98 octane which is about 93/94. I use the Super when I can get it but not all gas stations sell it here. And BTW, I pay way more for gas over US prices so its even more of a decision to buy higher octane.

 

Shell hightest, always (its at least 91, not sure if its 93) and Techron or SeaFoam once in a while.

The Ethanol can also dry out many plastic parts and fittings along the fuel system (they become brittle). Not much we (here in the US) can do about it, they're gonna add it anyway.

Maybe some of the newer cars have fuel system parts that are made of a plastic that is less effected by the drying that ethanol causes, but I think our (the C5) stuff is a little dated for that.

 

93 always... My company pays for my fuel...

 

93 always with the Maggie and not sure how true it is but on the fishing forum I'm on someone posted that E85 was knocked down. Its not suppose to happen.
With driving your vette often the E-10 is not going to be as much a factor as a unit that will be sitting for a long time like a boat over the winter or left unused for several months. Let hope for the best and keep our fingers crossed this e-85 won't happen.

 

I feel lucky. We still have two stations that sell 93 octane real gas without ethanol. Cost is the same as the government diluted 10
% gas.

 

Used 93 when we had it here...now 92. I also add Techron every now and then too.
I don't drive the vette enough to really have any savings by using the middle grade or regular.

 

93 almost always

 

I use 91 octane in mine as that is all that is available here. I have on occasion used 89 octane, and did not notice any decrease in performance but I didn't really push it hard either.

Our gas has 10% ethanol in it - not anything I can do about that as it is mandated by state law.

And as far as Techron goes - it is a fuel system cleaner. More importantly, it can be used to help keep sulfur deposits from getting on the fuel sending units and causing your gas gauge to go bonkers.