What kinda gasoline you take?

[Jolly Roger VX'er]

I run super cause of the SC, anyone every run mid grade with the SC?

And you can run 87 octane as the engine will retard timing (and power) accordingly. I cheat and use low octane during the week and 93-100 octane on the weekends.

87 is what the book calls for. Supercharger recommends 91+ but our knock sensor is able to handle the lower octane (with noticeably less power) without damage for those with the SC trying to save money...

I'm pretty sure that the mixing occurs at the pump/station - they only have two tanks in the ground too. It is usually cheaper to mix it yourself - do two transactions, one from the regular and one from the premium.

Hi Cyrk...based on all the above I've been alternating fill-ups from 1/2 tank between premium Amoco 93 and regular 87 during the week for regular driving; and running most/all of it out by the weekend or vacation and filling up with pure premium if I'm off and planning any "fun" driving excursions. So far no ill-effects, but, I keep my foot out of the boost to avoid any issues until I know I got a good fill-up of 93.

[spaceCADETzoom]

Yep, generally speaking, if your engine doesn't knock, 87 is just fine. It's a common myth that higher octane means "better" fuel...My VX fill just fine with 87. I have an RX7 that doesn't take anything under 91 and used to have a 240z with the same cultured tastes. We're really talking about the difference between Dasani or Evian and Arrowhead or Sparklets (or even tap). My rotary sportscar won't drink anything but the expensive stuff...ditto for my old 30 year old classic. THe VX, on the other hand, is a spry young thing that is just fine with the normal stuff. The 7 was designed for it...maybe the engineers thought we wouldn't think its a real sports car unless we spent more on it And, yes, higher octane would actually increase plug buildup.

just my 2 cents. i guess there's room for disagreement. sometiems we feel better doing certain things. i am certainly guilty of this.

I didn't even know we had a rating system...does it do anything? I don't see where I can see a poster's rating. I think you got a response about the octane thing because of the way your initial message came out, ritchiedon. Both the way you said it and what you said contributed to someone chiming in. (i.e. the "duh" thing and a subtle implication others would be dumb to fill up on 87)

I don't know about the neg. rating though...that may have came form anyone. Like i said, i didnt even know we had a rating system...and still dont' know its practical purpose. Don't worry too much about it...just a silly number that I don't think anyone pays attention to.

cheers.

[jimbo]

I usually put regular in my VX but every now and then I've tried premium thinking it was "better", and nothing is too good for my baby.

My VX always seemed like it ran a little better, peppier, when I put a full tank of El-Premo in; but I guess that is just my imagination.

No sense in wasting $$$$$$$ , our gas expenditure is high enough already.

Our other car, a VR4, requires premium, and certainly sucks up the gas, slurp-slurp

[Heraclid]

I was running 89 octane mid-grade all the time until just the last few tanks and was happy with it. However, it sure seems like my VX is actually running a bit better on 87 octane now and I've made no other changes to cause that. Plus the weather is getting warmer which usually seems to take the pep down just a tad, but the VX seems slightly peppier. Not a huge difference mind you, but I think 87 may be better for the non-SC'ed folks. The only difference I really felt with 89 octane was right after fill-up, which had nothing to do with the grade of gas. I think the fact that it has a full tank makes it a little peppier for some reason, but I don't know why. Maybe the fuel pump isn't working as hard then and/or the fuel pressure is increased?

[kpaske]

I've run 87 almost exclusively since I bought my VX new in '99. On the few occassions I've experimented with higher octanes, I didn't notice any better performance and actually experienced a decrease in gas mileage. I have running into knocking a bit, especially as my VX has started to get a bit older (I'm at 90k+ miles), but the brand of gas I buy seems to make a difference, so I try to avoid certain brands (ARCO in particular seems to run pretty poorly).