View Full Version : is it worth is to buy premium gas?

05-21-2002, 08:28 AM
on an 86 lxi? right now i just buy the cheap stuff, and i was wondering if it would smarter, or get me a little more performance if i went with premium, and this is on a bone stock car... heheh

05-21-2002, 09:27 AM
If your engine doesn't knock, you don't "HAVE" to get a higher grade. I noticed it runs smoother with 89 over 87 but 89, 91, 93 are all the same so I think going higher than 89 is a waste but this is just my opinion. I get 87 right now.

05-21-2002, 09:51 AM
If you don't knock on 87 you are fine with that. My 89 LXi always knocked on 87 so I have been using 89 since it was new. The LXi's have slightly higher compression that the DX's or LX's. The knocking sound is very faint so listen carefully and make sure you are not hearing any. If you are not stuck in one of the big cities where they are using reformulated gas (pretty fuckin' close to water) it would explain why you are able to run OK on 87.

Moving up to 91, 93, etc. will only drain your wallet faster and will not help your performance or mileage.

POS carb
05-21-2002, 11:03 AM
compression ratio plays an important role, 86-87 LXi's had the lowest compression (8.8:1), carbed accords of all years had the same (9.0:1), and 88-89 LXi's had the most (9.2:1)

For an engine with (basically) the same internals (ie. 87 LXi vs 89 LXi) higher compression will require higher octane fuel. Therefore I'd recommend regular for any 86-87 LXi's and 91+ for 88-89 LXi's <edit> I think that's what the manual recommends <edit>
My 87 carbed likes 89 but the ignition timing is modified

Note: I'm not saying compression is the only factor in determining fuel requirement, I know there's also rod/stroke ratio and combustion chanmber shape and quench areas and ignition timing and yadda yadda yadda, I'm just saying that in the case of identical engines changing the comp. will change the octane requirement. If you build a motor right you can do all sorts of stuff to lower your octane requirement (I've seen a dyno-proven 400 hp 351 Ford with a 10.0:1 compression ratio that pulled that number on 87 octane)

05-21-2002, 06:29 PM
I've put 87, 89, and 92 in my tank before, and I've found that 87 runs the best. With 92 my car seems kinda sluggish, and gets crappy gas mileage. My car (89 LX) loves 87 :).

05-21-2002, 07:39 PM
maybe your car runs slow on 91 because its more combustible so it burns quicker? or is it the other way around.

05-21-2002, 07:44 PM
It's slower combusting, cause it's "thicker"

3rd GEN
05-21-2002, 08:00 PM
I just run the cheap stuff in mine..
or it depends on the price... if it's cheap.. then I will put in 89..

but normally i just run 87

05-22-2002, 04:17 AM
If I dont run high test I get valve train noise, but I think this is more a symptom of my needing to adjust the valve clearences than the gas. With 91 and slightly advanced timing, I run nice and smooth and make good power, pus I get about 360 miiles to the tank.

05-22-2002, 05:03 AM
With 87 I'm gettin anywhere between 413.4 and 445.2 (26-28mpg) more leaning towards 28MPG. So possibly you might want to have things checked.

05-22-2002, 09:28 AM
damn!!! Then I really need to get things checked because I only get 220-240... but I'm constantly on the gas... racing and screwin around and stuff... I run 91 though and I like it much more then lower octane fuel... An occasional 32oz of turbo108 and I'm ready to go....:super:

05-22-2002, 09:42 AM
well i have always put the cheap stuff in, and so has my dad (just got the car a few weeks ago) and i guess its easy to get 400+ miles out of a tank, so i am not doing too bad there!

05-22-2002, 09:48 AM
You also gotta remember, the 89 LX is supposed to get about 27MPG (mine gets 28) and the LX-i around 25. Also, our tanks are 15.9 gallons (US) which is frekkin huge for the size of our cars! I always thought it was like 12 or 13, so I was filling up around 220, but now I wait till around 330 or a little more before I fill up. That and I can get 87 octane gas for 1.25 around the corner from my house :). Plus and Premium are the same price there too, for 1.35, which is a hell of a deal.

Jareds 89 LX-i
05-22-2002, 09:59 AM
I've always used either 87 or 89, and never really noticed a difference between the two. I have tried 91+ before and also didn't notice any difference. Right now I go to the Citgo station, where they don't have 87, they start at 89, and it's usually cheaper than everyone else's 87, lol.

When I was in Colorado I filled up with 85 octane, and it even seemed ot run fine on that too. I guess my car just ain't too picky :p Oh and I've been averaging about 30-33 mpg, so that's pretty good I believe

05-22-2002, 10:08 AM
well the fatorcy users manual for my car says it wants 91 or better anti-knock

05-23-2002, 07:46 AM
i've found that mine runs best when i half and half mix 87 and 89

89 or higher alone runs terrible, and i get worse mileage

05-27-2002, 07:28 AM
Originally posted by YK86
If your engine doesn't knock, you don't "HAVE" to get a higher grade. I noticed it runs smoother with 89 over 87 but 89, 91, 93 are all the same so I think going higher than 89 is a waste but this is just my opinion. I get 87 right now.

Might be a stupid question....but what do you mean "knock"??
Mine is more of a slapping i think..