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Best fuel for turbo Subarus?

15K views 39 replies 23 participants last post by  vintage42 
#1 ·
In my area there is a Subaru speed shop that only recommends Shell and BP Premium for the turbo cars. Well the other day my car after 10 miles of a Shell 93 fill up went to missing like crazy and set off a check engine light . 4 days of missing like crazy especially when cold and then by the time I get it to the dealer they find Nothing wrong.
Next I find out that my local Shell is an independent station and has ethanol in all gas . My understanding is that Subarus are not designed to run ethanol at all because of some cat issues. Subaru dealer said they are having a few customers with issues like this because of the relaxed standards on gas.
So what gas should I use?
 
#2 ·
Personally in my area I've found my forester runs the best when I fill up at Hess or Exxon. It also seems to run the worst on sunoco. I almost always goto BP when I'm back in NJ as on certain days they have 10c off per gallon on premium and the car runs great there too. Also up in NY every station is 10% ethanol and it definitely doesn't run as well on it. I avoid shell as much as possible, way more expensive than any nearby station and it runs the same or worse (v-power 93 isn't really anything special).
 
#7 ·
After 90 fills in 9 months, My Forester has only seen Esso once, Petro-Canada three times, and Chevron once.

That leaves 85 tanks of Shell V-power. Now, I don't know if other gas brands make it drive crappy or anything, because obviously I have no experience with them. But I have zero complaints about V-Power.

All are 91 of course. I don't think I've ever even seen a 93 dealer.
 
#8 ·
Hmm I've used Costco for some time now, and it's 10% eth gas. Though, I have to admit that my car is noticably noisier on Costco gas. I'm usually a Chevron guy. But then again, all CA gas is 10% eth I believe.

Hmm Costco gas is actually any brand of gas they can get on the cheap that day.. so could be mostly ARCO here..
 
#11 ·
Interesting. I generally don't fill up at Sunoco, I tend to stick to Exxon and Mobil, and I usually fill up at the same gas station. I'm really particular about my gas too. If I fill up at a station that has 92 as its highest octane, I will also go inside and buy a bottle of octane boost.
 
#15 ·
Interesting topic. I found that using Sunoco I was unhappy with my mileage. Then recently I switched to Petro Canada and my mileage improved immensely. The computer even showed it: 10.2 L/100km on Sunoco and 8.4 L/100km on Petro Canada. That is quite a difference! But believe it or not, it's true.

Geezer
 
#16 ·
^^I know tuners that swear by sunoco.

Personally, I have used many gas brands, and really the only difference I could find is in the "name" brands compared to the "discount" brands.

Also, I doubt it is an ethanol issue. I have run and tuned both my Subaru's on E85, and they run better than they run on gasoline. Smoother, more power without more boost (its a timing issue), a ton more power with more boost.
 
#19 ·
BP ultimate 98.
The mobile 97's ok if I can't get to a BP. I tried gull because it's 10% ethanol biofuel and thought I'd be enviromental but it only got 390km on 45L even though it's rated 98.
BP gets me 9.4/100km. All with the same kind of driving and speeds.

just out of interest what are fuel costs in the US?
Over here in NZ$ 95oct is $1.44 and 98 $1.49 which is roughly $1 and $1.05 US I think
 
#22 ·
It really depends on where you live. FWIW, Shell and BP have done me well and the local Cenex gives me good fuel, too. Heck, for all I know, they all get their local stock from the same supplier around here.
 
#28 ·
I almost always use Shell 93.

Running Stage 1 I did a 58 mile run to Long Island to get my springs installed, according to the Cobb AP I was getting 21.6 miles MPG and that's in mixed driving with lots of boosts here and there.

And in Stamford CT its about $2.29 per gallon.
 
#31 ·
I was never a Chevron guy before, but that is all I use in my Subaru now that it's price is same or less than others. My tuner commented on this gas working very well on my car when he was tuning it. Highest octane we have here in California is 91 and it all has at least 10% ethanol.

Seems Chevron and 76 are usually recommended by Subaru owners around here. I stay away from Shell as do many others. Too many reports of knocking after filling up with Shell, and stations not being consistent.

Stan
 
#32 ·
I was thinking... we could have fun with this thread.

It's common knowledge (is it?) that the Toyota Prius runs off of pixie dust and unicorn farts.
What would a turbo Forester run best on?

Or better yet, what would Smash's Forester run on? Somehow it has the power to keep itself outta trouble...
 
#37 · (Edited)
E85 is not the same as the crap ethanol blended gas that a lot of stations are going to. If you're tuned for it, straight E85 is awesome.
If I put 91 blended with ethanol in my XT, it freaks. I get terrible rumble, misses and horrid gas mileage. Husbands car is even worse (Stage 3). Luckily, you can still buy 100% gas here. if I couldn't get 100% gas, I'd get my tuner to fix it so it wouldn't run like crap on the ethanol blend.

The shells here have terrible gas. We use Phillips 66. If we drive to Texas, we get Chevron (my dad's station is a Chevron). I get super excited when I drive to Dallas and see 93 octane. I get much better mileage on 93.
 
#38 ·
E85 is not the same as the crap ethanol blended gas that a lot of stations are going to. If you're tuned for it, straight E85 is awesome.
If I put 91 blended with ethanol in my XT, it freaks. I get terrible rumble, misses and horrid gas mileage. Husbands car is even worse (Stage 3). Luckily, you can still buy 100% gas here. if I couldn't get 100% gas, I'd get my tuner to fix it so it wouldn't run like crap on the ethanol blend.
Lucky you, it's all 10 Percent here :icon_frown:. Even makes my humble N/A rumble weirdly and lose mpg.
 
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