I was reading through the manual last night and I found the car require Regular(87) octane at a minimum. Here in Texas, our octane ratings are about 1 different. Regular here is 86, for example. I also read it isn't recommended using Regular of 86 octane or less. Even though the manual clearly states that, considering Texas has this weird octane rating, would it still be a bad idea to run that 86?

 

It probably wouldn't hurt the car, but I would try and stick with 87 or up for best performance. You might get some pinging and spark knock under a load, which is not great.

 

Get a CAI w/tune, then you can safely use any octane... preferably the highest

 

Humm talk to your dealer about it maybe they will retune your car for the octane or give you a tuner not. I'd ask it wount hurt.

 

How about use 89/91/92/93/94/95/100 or whatever, instead of losing performance?

 

On hot days on 87 I hear a detonation ping once and a while but the computer instantly adjusts, so I started using 89, no issues. That way if the gas is not the greatest it will at least be over 87 octane.

 

At this point, I am pretty much convinced to move up to a higher octane. I appreciate all the help. =)

 

I have used 89 in both my '05 GT and my '07 GT/CS, never had a pinging issue with either car.

 

Wow, bizzare, we have 87 in the Dallas area.

 

ALL that oil in Texas and you cant get 87 octane?

Whats the next up? 89? I say put that in.

 

That must be limited to your part of Texas. I've been over many parts of Texas and have never seen anything less than 87.

 

sometimes if I had changed the octane when the tank was almost empty , I would disconnect the battery cable , then reconnect and I think then the cars pc readusts and it runs fine , as oppsed to not having disconnected. My opiniob and do not know its merrit but I can sense it !

 

uh, we have knock sensor's in our 3 valve's. 86 will eventually set them off. go up to 88/89. No higher though, without a proper tune applied. The higher the octane, the more additives in it, supposedly to help you run and burn cleaner. But. it will only retard the detonation, end result, you'll be pushing unburned fuel out the exhaust and burning out your cats.

 

86, 88, then 91 octane. Its weird, I know. I'll be moving up to 88.

Tuning. Will this give any sort of warranty issues?

 

I usually put 3-4 gallons of 93 in with the 87 when I fill it up, just to make sure it is wwell above 87 in the summer heat.

 

Interesting, I've never heard that before. Do you have any further material on this I could look into?

 

Mine was pinging under load using 87 all the time ...switched to 89 no more pinging. Besides, who ever heard of a high performance engine running on 87 octane?

 

I would suggest reading the information pertaining to Top Tier gas (see the link below). I have been using one of these brands for years, without a problem. While in Texas, I used Shell, but they are not in Western South Dakota, so I am using Conoco/Phillips. I hope this helps to clear up some of the questions on what octane to use. And, yes, you will pay a few cents more for a Top Tier gas, but in my opinion, it's worth it, based on my experiece.

Since the V8 is designed to run on Regular, I have been using Regular without a problem; however, the gas in your area may be reformulated due to emissions laws, and that may have an adverse effect on mpg, power output and pinging.

I am fortunate, in that I live outside a Metro area, and can obtain pure gas with no reformulation or alcohol added, unless I chose to use a mid grade with 10% ethanol. My on board computer has been reading a steady 23.4 mpg, and that is with a mixture of interstate (75 mph) and city driving.


http://www.toptiergas.com/deposit_control.html