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?
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).
I've never had a problem with Mobil, Exxon, BP, or Sunoco. All the gas in my area says it could have up to 10% ethanol though. Are you modified or tuned?
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.
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..
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.
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.
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.
But the timing you get from it results in more power.
A 25% mix is perfectly safe (provided you have the injector headroom, and a "stage 2" does) and will allow your ECU to max out the ignition advance multiplier. Figure on a good solid 12-15whp.
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
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.
I typically run Shell 91 octane here in Canada. But there are a lot of people that swear by the Sunoco Ultra94 on their custom tunes here. I'm most likely going to have to run Sunoco Ultra94 when my stage2+ is installed this spring
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.
Here's a related question: would you benefit from filling with a higher octane (97 or 100) right before you go to a track? Or maybe fill and drive around for 15 minutes to learn?
it will take longer than 15 minutes, and also just like with ethanol, unless you running some way of adjustign timing, the stock ecu cant compensate enough .. one real benefit is runnign more boost.. but that would help more if you were tunign yourself..
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.
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.
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.
You have insufficient privileges to reply here.
Related Threads
?
?
?
?
?
Subaru Forester Owners Forum
2.5M posts
188.6K members
Since 2006
We’re the best Subaru Forester Owners Forum to talk about the best years of the Subaru Forester, modifications and reliability history of the Subaru Forester.