Sorry but i own a mercedes, but you guys sure know your stuff. I want to know how i can mix pump gas with AV no lead fuel or some other mix that will bump up octan and still be safe for cat. and 02 sen. The car needs 91/92 octan know but just bought it and it has been running on 87 and I just want to run a high mix throught it to help clean it out .

 

I could be mistaken but by AV you mean aviation gas? I don't believe there is such a thing as avgas in "no" lead, only a "low" lead. The low lead still has enough lead in it to foul the o2 sensor and cat.

 

You need 91 Octane?

Buy premium gas.

Toluene will bump the octane (it's like 112 Octane, AFAIK) at the risk of causing cancer.

If you want to "clean the car out", buy a bottle of STP fuel system cleaner and dump it in with the proper octane gas.

 

I know about the stp but never have trusted any of that stuff. I would like to run higher octan in it. I used to be able to buy race fuel local but not any more. Toluene is a good altern. to bump up octan.

 

I have a spreadsheet at work where you just plug in the numbers (gallons, price, etc) and it calculates the resulting octane mix and price/gal. Email me at paul.chang@amgreetings.com and I'll send you file.