What kinda gasoline you take?

[Tone]

There will actually be MORE plug build up running hi test since the engine cannot completely burn all fuel and will run cooler than designed. Isuzu did NOT design for availabitity of fuel, please, but for what the motor was designed for.

How do you know VX Crazy gave you a -? What was her comment? Since someone can only give one ding at a time, two others didn't like your post either.

[RitchieDon]

Thanks for calling me on this one, Tone. I don't understand this reputation thing. All I can tell you is I saw I had a -3 rating and the only message there was the one from VX crazy which I quoted in the previous post. The people on this site have been very good to me and I don't want this to blow out of proportions. My apologizies to anyone I have offended.

[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).

[RitchieDon]

I hate to bring this subject up again but I really have a need to do so. After my posts on this matter I got several nasty-mails. One of them suggested that I get my facts straight. I took the advice and have talked to mechanics, engine technicians and specialists. Here is what I have learned.

First off, everything I have said on this matter is wrong. These engines were designed to run on the lower octane. Putting better fuel in the engines is a waste of money and can actually decrease your performance and fuel milage. I have waited until now so I could experiment with what I was told and I can tell you that after going from 91 octane to 87, my fuel milage has jumped from below 14 mpg to around 15. I have not experienced any knocking.

The car had a newly overhauled engine in it when I bought it and I have been breaking it in with conventional oil as I was advised by the rebuilders to do so. I now have about 8,000 miles on it and am going to switch over to synthetic. This should increase the mpg to average between 16 to 18 which is the best I could hope for.

I stand before you admitting I was wrong and spoke on a subject that should have had a little research done on my part. Send me more negative reputation points. I deserve them. I am taking every word back one byte at a time with ample amounts of crow sauce. I am working very hard to suppress my contemptious nature and will try to be a positive contributor to this site.

My subscription to this site is due and I will make my decision to continue to be a part of it depending on the response of the members. My signature tag pretty well sums it up.

[WyrreJ]

My subscription to this site is due and I will make my decision to continue to be a part of it depending on the response of the members.

You were doing remarkably well this time - most would have just kept quiet after learning the facts from the experts, instead of publically correcting themselves for the education of others -- until you got to that part. Hints of blackmail are never endearing.

[thebear54]

I still use the old method I learned from my father who learned it from his....
About every 4th tankfull I will go the Super and add a bottle of injector cleaner. I average 21 to 23 MPG with my VX, which is way above normal for city/highway driving. I just completed a 405 mile round trip to Brookline, MA from my house in Mt. Tabor, VT and I still had about 3 gallons in the tank when I refueled. Maybe I just got lucky with my 3.5
John

[thebear54]

PS....RitchieDon,
It takes a big man to admit when he is wrong and an even bigger man who makes it right.
My hat is in your corner...the rating system(although sometimes funny, it can also hurt)should not be used to "castrate" someone for their opinions or statements. If facts are wrong they should be PMed first to set the record straight.
THAT'S MY 2 CENTS
John

[RitchieDon]

Thanks for your support John. I am only trying to get things right. I was out of line and I certaintly don't want to put bad information out to those who are in the same situation I was in when I oringinally came to this site looking for information on my VX. Wyrrej suggests that I am trying to blackmail the members? I'm just trying to admit that I spoke without knowing what I was talking about. High octatane fuel was needed in the old days when the pavement pounders that I was used to needed it. Things have changed with the computerized ehnanced engines.

[technocoy]

I don't know ritchiedons past on the board but i think it may be a little wrong that people are giving him any kind of flack for stating an opinion that as far as he knew at the time was true... I have heard ten million DIFFERENT "facts" about fuel grade. i don't think he did anything out of line at all, and it dissapoints me that the VX family would so quickly condemn someone for such a petty thing. of course i may not understand the situation at it's core.

just my 2 cents.

technocoy