I know this question could go any anywhere...but I have a sedan, so here it is! ...don't flame me on this question, I think it's a valid one!

Just wondering what everyone uses in thier G....87, 89, 93.....aviation gas?!? My thought is, why would an engine that is variable valve timing, as well as having an onboard cpu that puts a Cray to shame, need anything higher than 87 octane? Personally, I used 87 octane, and have never had a knock or ping. And the dealer.....they said that they only use 87!

I think I should just convert my G to CNG....now there is an octane boost for ya!

Thoughts?!?

 

I have used everything except 87 with this car. The manual recommends 91.

 

Manual recommends 91. My car hasn't had anything in it but 93

 

I use whatever the manual recommends/requires. 91 recommended, I use ethanol-free 93 since it is available in my area.

 

I'm in the same boat as yevi.

 

I don't think you are getting any knocking/pinging because the computer is retarding the timing. You may be losing some power and efficiency however.

 

It's not a dumb question but it has been asked, answered, and discussed ad nauseum. Search for people's thoughts.

Cliffs: The car is designed to run on 91+ octane and it is called for in the manual so that is what you should be using. If you want to use 87 it's safe to do so but performance will suffer.

 

Octanage has to do also with compression, high compression engines need higher octanes. Pull you spark plugs, I bet they are redish which means that the combustion chamber has been running way too hot. I had an A6 a few years ago and put nothing but 85 in it, I burned up up 2 coil packs in 2 years that were unexplainably 'burned up'. They sit right above the block.......