soo what gas do you guys use? i was reading something last night (cant remember what thread it was) but it said something how someone tried 96 octance fuel and got worse MPG... he got like 16mpg and it was all freeway... also something about how the high octane causes harder ignition?

im asking this because ive been usign shell v power which is 93 octane... and lately my cars been running funny. could it because of the gas? should i switch back to mobile 91 super?

 

winter formula maybe? I believe they change something in the fuel for the colder months.
I've pretty much always used Shell 91 octane (highest octane most stations carry in CA)

As for mpg... oh boy, lets not go there.

 

I can regularly hit 22 mpg freeway miles on 93. On 92 I got in Ohio? 22 mpg. It has more to do with your engine and then the octane. You either have a high enough octane or you don't. If you poke around, you'll find people running 87 without issues. Energy content of the gas is a chemistry discussion most people wouldn't find interesting. So, if your engine is running funny on 93, you either got bad gas, your car doesn't like winter mix, or your engine is just running funny.

If it persists through a couple tanks, I'd get your car checked out. I switch between Mobile, Sunoco, and Shell regularly. I'd wager the winter mixes they use are very similar.

 

Yeah, you probably got a good dose of winter gas.

I wouldn't put much credence in the "high octane burns slower" theory, it is simply more resistant to detonation (which has nothing to do with normal combustion or power, or "hard-to-ingiteness" )

I have run a whole tank of 115 and just got exactly my normal mpg (around 19 overall). Sad, expensive, but true.

S

 

I've used Shell 93 since 00' with my Jetta. It's the only gas I use.

 

I use either Exxon / Shell 89 Octane except for track weekends when I use 93 of what ever is near the track. I have 80,000 miles, get about 21 MPG and have had no major issues.

 

I use Chevron Supreme 93 octane, no problems. At least none that I seem to notice..

 

what kills me are the people who are like oh i average 20+mpg on freeway... my freewaympg changes like .5 what rpms are you guys cruising at on the highway?

 

When I kill a tank on the highway, it's sitting in 6th doing 3500-3800 rpms for hours. I've driven the car out to Ohio, Harrisburg PA, and Myrtle Beach SC. As far as tooling around town, I get in the high teens. I've been able to get as low as 11.4 with some near-tracklike driving. My mileage most definitely varies.

 

I run "top-tier gasoline" (Shell 93 most of the time) and a fuel additive from Lube Control called "FP60".

Top Tier Gas (http://www.toptiergas.com) meets an enhanced manufacturers standard for deposit control. Lube Control FP60 is a great lubricating cleaner (http://www.lubecontrol.com).

May seem like overkill, but this is what I do to get great cleaning power to help keep these carbon-generating engines free of build-ups (in addition to the Sohn/Idemitsu mod).

 

I've always used 93 and on trips that are 100% highway i've gone 320 miles before my gas light comes on (24mpg) that's keeping speeds around 70.

 

I always use 93 now, Between BP, Mobil and Shell.

I would say about 45% BP, 35% Shell and the rest are Mobil. Not because Mobil is far, actually its the closest one to my home. But usually I check prices before I do fill ups. call me cheap ok, the BP is about 4 blocks away from Mobil. and sometimes one is cheaper than the other, I tried a couple of times the differents is like as much as 15 cents !

Shell is nowhere close to my home, but its very close to my gf's home ... ahh you know why

Plus I add about 5-6 oz of Idemitsu before fillups ... no problems whatsoever

 

I agree with Jax RX8. Run a top tier fuel if you can. The deposit control is much better with these fuels in the long run. The reduced detergents in other fuels may be the cause of some of the port deposits blamed on synthetic oils.

 

87 bp / amocco. every 10k miles a can of b&g 44k. aggressive driving weekends. 93 bp/ amocco..

beers

 

I take 100 octane with 5% of ethanol, massive improvement in compare with 95 octane

 

sure,

blah blah blah.. where are you?

beers

 

Now keep in mind depending where you are they use the Ron Octane rating, Mon Octane rating or the average (US) (ron+mon/2) rating. I believe the Ron rating is normally higher then the mon so when averaged you get the ratings like what we see.

 

I'm in sydney australia. Liter of that fuel costs around $1.3

 

that helps and it makes sense now..

beers

 

^^



ah... too many beers eh Swoope? Now you understand.

 

AND WHY NOT?

I'd love to turn this into another MPG thread..

 

Shell V-Power here in Ohio. Its all I use.

 

Why doesn't anyone use ARCO?

Shell V-Power 91

 

BP Ultimate 93 (29%)
Mobil Super+ 93 (29%)
Shell V-Power 93 (29%)
Others including Sunco, Citgo, etc (12%)

 

Mine runs fine on 87, never used anything other than Mobil, Shell or Sunoco. Tried a few tanks of 93, no noticeable difference, mpg stayed the same 16 city 21 hwy.