Is everyone using 91 octane?

[Chsmadden]

Quote:

Originally Posted by tulsalfa I ran one tank of 87 octane gas (by mistake) through my 86 Grad with no noticeable effect. I do add a bit of Lucas Gas Treatment with each tank. Has anyone had any experience with running less than 91 octane gasoline? Will the computer reset for the lower grade? Am I causing some unseen damage by running 87 octane either4 sporadically or even constantly? Any advice would be MOST appreciated. Dean

[maxwedge]

I run 87 in all my vehicles, even though the turbo Celica says "Premium Fuel Reccomended for best performance". Of course, they wrote that back in 1989 when gas cost 1.10/gal. It's been running fine on 87 for 20 years and 170K highly abusive miles. I noticed last night when I filled up my truck last night it was almost .50 more (4.15) a gallon for premium here in IL. Which reminds me, does anybody want to buy a thirsty, high compression V8 powered jet boat, with a 30 gallon tank?

[Garry-Graig]

Quote:

Originally Posted by papajam The half dozen or so mid 1970s 2000 Euro owners manuals I just looked through all recommend the use of premium fuel (no octane listed).

[Oski_Bear]

Dang..and here I am using 91 all the time.... time to switch!

[Chsmadden]

10.4:1 Pistons is probably a bad candidate for 87 isn't it.

[Bill77]

I've heard that the 10.4:1 pistons like to be run on 91 or more, but haven't tried it on my yet-to-be-started (and yet-to-be installed) 2L.

I'm curious what others will say...

[Giovanni2000]

I run 87 in my 82 Spider with no problems, 87 in my Honda, 89 in my Infiniti and 100LL in my Skyslug I mean Skyhawk...I have noticed a difference in smoothness between Chevron and Shell, so I use Chevron as much as possible...

[lowmileage]

Nothing but 93 for my baby

[msiert]

I'm using 92 gas in my Spider w/o knocking and I have a 10.5 CR....................Can't find 93 in Nebraska.

[BlueSpider]

Very interesting. Question I had for sometime. I am using 91 all the time on my 88 Spider and I know previous owner was running on 91 as well. From what I read it appears I am wasting money more than anything else. I shall try 87

[Andrew]

If your timing is reasonable, my experience is you have to be pretty abusive to get a Spica car to ping or knock; they're pretty resistant to it. Carbed cars will ping more easily.

I use the highest octane I can get, which where I live in Calif. is 91. I think 87 is asking for trouble, unless you're at high altitude, which 1000 Oaks is not. Make sure to keep your ear tuned for pinging or knocking while trying 87.

Andrew

[Andrew]

Thought, but did not state: I am not sure how sensitive Bosch cars are. L-Jet cars do not have knock sensing and cannot retard the spark if pinging is detected. Motronic cars I don't know about.

Andrew

[BlueSpider]

OK noted. I have L-Tronic indeed. I am happy to stick with 91 if that's what is best. Let me have a chat with my mechanic later today. Thanks again.

[Andrew]

If you're aware of the hazard, and know what to listen for in knocking and pinging, I don't see the harm in trying 87 to see how it goes. If the car is loud, or there's lots of wind noise, you do risk not being able to hear pinging or knocking. But I'd expect you'd be OK if you go carefully. Of course, if you drive too carefully, it won't knock or ping.

To get knock or ping, try the proven combination of low rpm, large throttle opening, and high ambient temperature. Guaranteed to ruin your engine. Also hard on rod bearings.

My wife's 97 BMW 328i pings on Calif sea-level 89 octane; not sure what generation of Bosch engine management it has; Motronic something, and presumably knock sensing and spark retard?

Andrew

[BlueSpider]

Thanks Andrew - and no I'm no expert in determining the knocking thing, unfortunately