utkinpol

cheater you`re not supposed to run race gas in a non-race prepped car.

Spokane5150

I never like Shell gas. My cars seem to run poorly on it going way back to my 1996 Buick Grand National. I like BP, Exon and the best is Sunoco 94.

GSIRM3

Shell gas makes my 2012 GTS put out a lot more soot on back bumper than other brands.

Dr. No

It can, but only at the risk of moving this thread to P&C.

Macster

While Shell gas has been ok for me, and my cars, there are possibly regional differences and vehicle differences as well and Shell may not be quite as good as where you are, or maybe other gasolines where I am are just poorer than Shell.

You did the right thing experimenting with different gasolines and if you have found the car likes BP or Exxon or Sunco then feed it one of those gasolines.

Sincerely,

Macster.

VGM911

There are only a few reasons why living in New Jersey could be better than living in California - and Utkinpol has pointed out one of them! (of course, a second reason is that we have an abundant supply of 93 octane gasoline)

cannon1000

I don't have this problem on georgia, but are octane additives a no-no?

Octane does not equal quality so i am not sure if the additives of these bottles differs much from what they are adding anyway.

Any thoughts on that to help the cali peeps?

Deansdream

Couldn't find 93 during lunch last year at Mosport. Gave up and filled w/91. As it had finally stopped raining, put on the Hoosiers. Next time out, actually lost time up the back straight. WTF?? Oh, yeah, I put in 91.

Probably won't notice street driving. But you sure will on the track.

alexb76

So, ALL OVER CA, you cannot find 93 octane? or just very limited?!

I guess we're lucky here, as have Chevron 94 octane option with 0% ethanol!

rockrich

Guess I'm gonna have to take my 2008 meteor grey C4S up to your neck of the woods so I can sip some of that good 94 octane Canadian fuel!

Spokane5150

Wow....you would know with that beautiful white car. That is interesting. I wonder what they do that is so different than the rest of the gas companies. I think it is regional too because states like California don't have a winter blend. I'm not fond of BP based on their poor management in the Golf and I don't like Shell so I'm trying to stick with Exxon as much as possible.

Oh boy...I forgot about Exxon Valdez. Time to buy and electric car or convert my 911 to run on natural gas.

Macster

Generally my thinking is if I'm buying a gasoline that needs additives I'm buying the wrong gasoline.

I haven't bothered to work the numbers, do the math, but I suspect it is quite a bit cheaper to simply buy the right octane grade of gasoline.

Now I realize you (like me) are in CA and 91 octane (barring the rare station that carries something higher) is all there is.

But both of my cars appear to have been unaffected to any noticable degree by running 91 octane.

To bump the 91 to 93 I think you'd have to buy a lot of octane booster. I've not looked into this, only going by what others have posted, but the octane boosters raise the octane not by full points (from say 91 to 92) but by a tenth fo a point, from say 91 to 91.1... If this is correct it is going to cost you a pretty penny to get to 93 from 91 octane.

The only time I use an additive is when I use Techron and I only use this every couple of years, for instance a month or so before one of my cars is due to be smogged.

However, the Boxster is due to be smogged in May and the car/engine is running very well and I think I'll skip the Techron this go 'round.

I might point out the Boxster is running very well at over 250K miles. Due to a sick relative I've been driving sometimes 100 or more miles per day sometimes several days per week and there for a few weeks almost every day! 700+ miles per week of driving.

The Boxster appears to have taken to this like a duck takes to water. The engine is running as good as it ever has. Too give the Turbo some exercise it gets the call every few days and it loves this 100 mile jaunt too.

I'm telling you people these cars love to be driven!

Sincerely,

Macster.

Mike in CA

I can't recall the last time I saw anything other than 91 at any "normal" California station. If I go to Infineon Raceway they have 91, 95, and 100 unleaded as well as even higher octane leaded race fuel. My understanding is that there are a few scattered stations (other than at race tracks) that carry the Sunoco or Unocal 100, but I haven't run across them. You are lucky to have the higher octane stuff readily available.

priapism

It's a supply issue. Every gallon of oil distilled can only produce so much high octane gas. When it's refined, if you take out the really good stuff to make 95 or better, the stuff you're left with is only about 85 octane. So they create blends to bring the minimum octane up to the usual minimum of 87, and 89. With only so much of the lighter stuff to go around, there's a limited supply of it available.

In the midwest, filled with pickups and low-rent domestic sedans, the demand for 87 is pretty high. That leaves more of the good stuff available to be blended. They can make higher octane because more of the lower octane is being used up, leaving more of the good stuff available. In California, full of Benzes and Bimmers and turbo cars, the demand for 91 / 92 is higher, so there's less of a supply of that good stuff to go around. Thus, the blend has to include more of the lower-grade stocks.

Hope that made some sense.

P0rsch3F113

+1 In Ontario I have to use PetroCanada (a Suncor Co. now) Ultra94. Car runs much better on that, unfortunately, than Shell91. Lately have noticed some PetroCan stations have shortages of 91 and 94.