You are correct kind sir but it's tough to enumerate. For example, my Honda Accord gets 1-2 mpg more using 89 octane vs 87. I don't even put 87 into my lawnmower or weedwhacker.

 

to add to the topic, simply look at the published figures for the new 302 cubic inch Mustang

HP Regular Fuel: 402 @ 6.500, Premium Fuel: 412 @ 6,500

Torque Regular Fuel: 377@4250, Premium Fuel: 390 @ 4,250

So if you want a quick and easy 10HP and 13 foot pounds, you use Premium


And that is with a factory tune. Imagine what you could get using an aggressive tune for premium fuel?

 

Does anyone know what octane I should run in a 86 Iroc Z28, with the original 305 (no mods except magnaflow exhaust).

 

everybody's a comic around here.

 

Why, what was funny? The fact that exhaust doesn't affect octane requirements?
86, your engine has 9.5:1 c.r. So, you're gonna want better than the cheap stuff, try mid-grade.

 

After your and my comments he asked the question. I simply thought he was busting our chops to be funny.

 

OKKKKK.....

Time for some background info. I have owned the car for a year now and have only seen it for one week out of that year. I have only driven maybe 1500 miles in it. The reason why I asked, was not about performance, more the reason that it was run on 87 for pretty much its whole life and I was wondering if that could have caused any damage to the engine.

This is not a $$$$$ thing, I have no need to save dollars at the pumps. I run my truck and other car on 91 octane. The main reason of asking is because if it needs to be run at a higher octane than I will need to start adding some Octane booster because where my car is located you can only buy 87 from all the gas stations within 70-80 miles.

So can anyone recommend a good octane booster?

Thanks again for the comments/input, it really is all appreciated

 

My local Waldomart carries octane boost, but I can get premo at the pump here.
No, your engine wouldn't have been damaged from running 87. If the knock sensor picks up any vibrations, it tells the computer to retard the timing accordingly to prevent engine damage.

 

Thanks
I wasn't busting your chops, just wondering because i've been running the car on low grade fuel for the past year. I'll try mid grade. thank you.

 

hmm never really did the math. ill probably never run 85 again now..haha