Which brand of gas is best?

..................For what it's worth, I saw a tanker at a Mobil station recently that didn't have any Exxon/Mobil words displayed on it.

You would be hard pressed to note any differences on any major brand gas from an active pump. Once in a while it is possible to get some that has some condensation in it, etc. But even then most all water is removed via filters at the pump.

It's largely your imagination. (especially when considering a low compression, VW engine.)

Jim

Low compression VW engine? What are those?

;)

Jan (8,7:1, 9.5:1 and 10.5:1)

...presuming the compression is low has gotten many people holes in their pistons. If *you* did not personally build it, always assume the compression ratio is high and run the best gas you can afford...its cheap insurance.

...Gareth

With most of my VW engines so far, I could be absolutely sure that Volkswagen built them. Stock configuration, even what's sold as Normal (regular) petrol in Germany is at least one level above what's needed.

Reminds me of a trip to the GDR (this is obviously an old story :-). On their gas stations, there were three kinds of petrol: Regular, premium, and two-stroke mix. Premium was about as good as regular(west). So there were, predictably, about 40 West German cars in line to the premium pump, about 15 Trabants and Wartburgs in line to the two-stroke mix pump, and a single Lada at the regular pump. The latter was then soon joined by two Bugs.

Earned us plenty of envious glances from out of the line of West German cars, and a nice discussion with the station attendant. "I would not do this if I were you," he said. "We need 87 ROZ," I answered. "Oh. You had that in the West too?" "Apparently they did, back before I was born." "Ah, okay. I see." :-)

Needless to say, we had no problem at all with that petrol. It was 88 ROZ, if I remember correctly. Plenty of a safety margin to account for 20-year-old engines. ;-)

Airhowlingly yours, Erik.

16 years ago I'd have said Conoco was the best gas you could buy for streetable Aircooleds......................They sold the same stuff for cars that was certified for Avaiation. I was once shown the certification for some near an airport..............same stuuf as in the local planes. But That was many years ago. I don;t see much use for 100LL on ACVW's either, but you could easily find some for yours if you can find a Small airport nearby that will sell you the fuel. The LL stands for Low Lead. You're car is likely not suited for such, but it wouldn't hurt I don't think. Juts very expensive.

Nowadays Fuel is most difficult to figure unless you're a chemist and have test equipment handy when you go buy gas.

The best term I can find for all th "BUY ME" ads is "Snake Oil"

Most fuels are so similar , one can't tell a difference, unless you live in a city or county that requires some kind of additive that screws with your fuel's burning properties. In Dallas, there has been such an additive and the best way around it is to drive far enough outside the County, that you use all the fuel you buy to get back to twon..................so it is of no use to try and get around it.

As it as though, try a couple of tanks of several fuels, record the Mileage and see what kind of temps and issues that may arise from using one instead of another. Settle on the fuel that *you* feel like serves you best.

Remove "YOURPANTIES" to reply MUADIB®

It's is not, it isn't ain't, and it's it's, not its, if you mean it is. If you don't, it's its. Then too, it's hers. It isn't her's. It isn't our's either. It's ours, and likewise yours and theirs. -- Oxford University Press, Edpress News

It's not cheap insurance at all. It is a double hitter to the pocket book. One, premium costs quite a bit more and two, premium will give YOU worse fuel mileage if your engine doesn't require it. Not to mention you lose HP with premium if not required.

We have done substantial dyno testing (engine and chassis). If you use an octane level higher than required you are losing significant performance (and $). If you are driving a car with no knowledge of what the the octane requirements are, you are even worse off. So buying the best gas you can afford is not cheap nor good advice.

For those of you interested. Here is rear some chassis HP numbers for a

1192cc, Formula V engine. (These are peaks at or near 5000 RPM, but the curves are similar for all.) (43 cc chambers with .040 deck height)

(stp corrected)

~ 52 HP with 110/115 Octane Sunoco Leaded Track gas. ~ 52 HP with 100 Aviation LL ~ 53 HP with ~91 Octane Non-leaded pump gas. (Lexington KY) ~53.5 HP with 87 Octane " " " (A/F ratio stayed pretty constant since the sg of all of these were similar, but actually jetting (and timing) was optimized for the track gas. So it is conceivable more gains could be achieved with the low octane stuff.

There are a few racing market fuel concoctions (T-104, C-4. etc) that also produced slightly over 53 hp, but they were $14 to $20 / gallon before shipping costs.

This engine produced about 58+ on the engine dyno. (The VW transaxle is quite efficient, as you can see.)

Tests on a 1600 Formula First engine. (Near stock specs) with a W-110 cam and 34PICT, produced similar results.

Jim SR Racing