Ok, I've done this before, and its always the same. I would mix 92 octane with 87, and always get more miles on a tank of gas.

Today, I made a 400+ mile drive. Normally, if I use either 87 or 92, I would normally get 250-280 on about 10 gallons of gas. I filled up today, had a little less than half a tank of 92, I filled the rest with 87. Well, I got 315 miles @ 10 gallons.

Its just weird because everytime I mix different gas octane gas, I get better milage. Does this make any sense, or is my car possessed?

Um..... the classics were designed to run on crap gas right? so the 87 stuff..... guessin you have bumped timing but not enough to warrent 92... so your car is happy with 89-90? total crap coming forth from my mouth....

Khiem

Originally posted by spdracerUT
total crap coming forth from my mouth....


Perhaps so. My timing is at 16 degrees. I'm not saying anything about my car having better performance with the 2 different octane gas, my car was full of stuff I'm taking to college. I just noticed that when I do this, I get better gas milage. This was also with the windows up and the AC on the whole time.

Actually, having your windows up with the A/C on is better aerodynamically than running 2/70 A/C... less drag equals better mileage.

When I used to live in the Panhandle of Florida, and went to school in Gainesville, I always noticed the same thing. From then on, on long continuous drives, I've kept the A/C on and windows up... especially at highway speeds. I even tested it with my old Honda. Got 37 mpg with windows up, got 33 with windows down.

Course if you want to get really good mileage, keep the windows up, and the A/C off.... sweating like a pig is good for you.

I think on my next road trip, I'm going to try do your half and half tank fill up. I don't think it equals out to 89 octane.... pretty sure there's another issue involved(got that itch in my brain, just too old to scratch it).

Later,
Mark

I've heard from many old muscle car guys that if you mix 87 with 93 or 94, through some alchemical reaction you get 96 octane. Don't know if it's true, never tried it myself.

It might be possible if you used 87 LEADED and 94 UNLEADED, but only if the 87 octane used a really crappy base stock that required a lot of tetra-ethyl lead.

TEL is dealdy stuff but does wonders for fuel octane. WW II aircraft power requirements led to research that led to 150/160 equivalent octane. Yes, you read that correctly.