E15 gas?
Team Owner
Joined: Jul 2004
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From: Hartford WI
Burning Brakes
Joined: Nov 2022
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From: MN
This is why I dont buy E10/E15 from the pump, well that and most of the E10 stuff is 87 E10 or 88 E10. I usually get either 91 or 93 and then add enough E85 to the mix to get the ethanol content mix up to E15. This way I start at 91/93 octane and then am raising it up to around 95-96 octane.
When I was mixing to hit E30 I had an ethanol tester I used to determine what the actual local E85 % was to ensure I got at least 30% ethanol. If you're trying get "up to" 15% then you're probably fine with the inaccurate E% in E85.
Team Owner
Joined: Jul 2004
Posts: 28,424
Likes: 3,276
From: Hartford WI
I just wanted to point out that E85 isn't necessarily 85% ethanol. Sometimes it's 'up to' 85% but often it's a range, like 55-75%.
When I was mixing to hit E30 I had an ethanol tester I used to determine what the actual local E85 % was to ensure I got at least 30% ethanol. If you're trying get "up to" 15% then you're probably fine with the inaccurate E% in E85.
When I was mixing to hit E30 I had an ethanol tester I used to determine what the actual local E85 % was to ensure I got at least 30% ethanol. If you're trying get "up to" 15% then you're probably fine with the inaccurate E% in E85.
Burning Brakes
Joined: Sep 2022
Posts: 1,202
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From: MSP
I just wanted to point out that E85 isn't necessarily 85% ethanol. Sometimes it's 'up to' 85% but often it's a range, like 55-75%.
When I was mixing to hit E30 I had an ethanol tester I used to determine what the actual local E85 % was to ensure I got at least 30% ethanol. If you're trying get "up to" 15% then you're probably fine with the inaccurate E% in E85.
When I was mixing to hit E30 I had an ethanol tester I used to determine what the actual local E85 % was to ensure I got at least 30% ethanol. If you're trying get "up to" 15% then you're probably fine with the inaccurate E% in E85.
Burning Brakes
Joined: Nov 2022
Posts: 910
Likes: 430
From: MN
On my WRX with MAPerformance's E30 tune it yielded 330 AWHP.
Correction: 321 awhp, 335 awtq.
https://www.maperformance.com/blogs/...-tunes-out-now
Correction: 321 awhp, 335 awtq.
https://www.maperformance.com/blogs/...-tunes-out-now
Last edited by AnotherNorskie; Dec 29, 2022 at 03:43 PM. Reason: Stupid memory
Team Owner
Joined: Jul 2004
Posts: 28,424
Likes: 3,276
From: Hartford WI
On my WRX with MAPerformance's E30 tune it yielded 330 AWHP.
Correction: 321 awhp, 335 awtq.
https://www.maperformance.com/blogs/...-tunes-out-now
Correction: 321 awhp, 335 awtq.
https://www.maperformance.com/blogs/...-tunes-out-now
Burning Brakes
Joined: Nov 2022
Posts: 910
Likes: 430
From: MN
About 100 hp and 120 tq more. Going from stock to 91-93 oct stage 1 wasn't super pronounced, but it did improve driveability. Going to E30 made a huge difference, primarily in the torque department.
That's coming from 2.0L ... imagine that sort of gains from our 6.2L.
That's coming from 2.0L ... imagine that sort of gains from our 6.2L.
Team Owner
Joined: Jul 2004
Posts: 28,424
Likes: 3,276
From: Hartford WI
About 100 hp and 120 tq more. Going from stock to 91-93 oct stage 1 wasn't super pronounced, but it did improve driveability. Going to E30 made a huge difference, primarily in the torque department.
That's coming from 2.0L ... imagine that sort of gains from our 6.2L.
That's coming from 2.0L ... imagine that sort of gains from our 6.2L.
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Burning Brakes
Joined: Nov 2022
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From: MN
IIRC Stage 2 required hard parts like exhaust etc. The 2.0 internals were good for about 350 ft/lbs, so going to E85 and a tune would have required new connecting rods, a HPFP that could push more fuel, etc. Then we can start to think about a closed-deck block, forged pistons etc. By then it's tuned out of class (in my opinion). If I had a pickup for a 3rd vehicle, a WRX on stage 1 E30 would make an excellent winter/daily driver complement to the C7.
Team Owner
Joined: Jul 2004
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From: Hartford WI
I don't have the car any more; but it was mechanically stock (the tune was the only change), and the WRX's are turbo's (and DI). Stock the whp was in the ballpark of 225 on 93.
IIRC Stage 2 required hard parts like exhaust etc. The 2.0 internals were good for about 350 ft/lbs, so going to E85 and a tune would have required new connecting rods, a HPFP that could push more fuel, etc. Then we can start to think about a closed-deck block, forged pistons etc. By then it's tuned out of class (in my opinion). If I had a pickup for a 3rd vehicle, a WRX on stage 1 E30 would make an excellent winter/daily driver complement to the C7.
IIRC Stage 2 required hard parts like exhaust etc. The 2.0 internals were good for about 350 ft/lbs, so going to E85 and a tune would have required new connecting rods, a HPFP that could push more fuel, etc. Then we can start to think about a closed-deck block, forged pistons etc. By then it's tuned out of class (in my opinion). If I had a pickup for a 3rd vehicle, a WRX on stage 1 E30 would make an excellent winter/daily driver complement to the C7.
It's only money and not mine?
I might be running for office. I am pretty good at spending OPM (Other People's Money)
Burning Brakes
Joined: Nov 2022
Posts: 910
Likes: 430
From: MN
Interesting. Maybe it is the stock tune that is kinda lacking? According to a post HERE, the gains weren't as much but there again, it isn't forced induction.
It's only money and not mine? I might be running for office. I am pretty good at spending OPM (Other People's Money)
It's only money and not mine?
I might be running for office. I am pretty good at spending OPM (Other People's Money)Audi did the same thing with their Q5 vs. SQ5 tunes to maintain the pecking order; same hardware, but the Q5 made ~270 hp whereas the SQ5 was 359hp. Throw a stage 1 tune on either and it bumps up to 430hp (or go nuts with hard parts and E40 and get 540 hp).
I wonder if the LT4 limitations are more due to airflow? 2 vs. 4 valves, maybe other pumping losses? Speculations.
On both my WRX and SQ5 the real benefits I experienced came from the torque gains, and with just software upgrades it's an easy and inexpensive thing to do. Spinning to redline for 0-60 times etc are purely academic and for bragging rights. The effortless thrust in the middle-rpm ranges are appreciated.
Team Owner
Joined: Jul 2004
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From: Hartford WI
Yes, I suspect the OEM Subaru tune left a lot of power on the table for reliability, but also so that the WRX remains 'below' the STI (just like GM kept the Camaro 'below' the Corvette in terms of performance). The WRX is sold in high-ethanol markets like Brazil (I believe 27% is the minimum?) so all the hardware can cope with that level. The STI had the older EJ25 block didn't have direct injection or HPFP so it needed more hardware to use ethanol properly, and even then it didn't have the twin-scroll turbo and other benefits of the WRX's 20FADIT.
Audi did the same thing with their Q5 vs. SQ5 tunes to maintain the pecking order; same hardware, but the Q5 made ~270 hp whereas the SQ5 was 359hp. Throw a stage 1 tune on either and it bumps up to 430hp (or go nuts with hard parts and E40 and get 540 hp).
I wonder if the LT4 limitations are more due to airflow? 2 vs. 4 valves, maybe other pumping losses? Speculations.
On both my WRX and SQ5 the real benefits I experienced came from the torque gains, and with just software upgrades it's an easy and inexpensive thing to do. Spinning to redline for 0-60 times etc are purely academic and for bragging rights. The effortless thrust in the middle-rpm ranges are appreciated.
Audi did the same thing with their Q5 vs. SQ5 tunes to maintain the pecking order; same hardware, but the Q5 made ~270 hp whereas the SQ5 was 359hp. Throw a stage 1 tune on either and it bumps up to 430hp (or go nuts with hard parts and E40 and get 540 hp).
I wonder if the LT4 limitations are more due to airflow? 2 vs. 4 valves, maybe other pumping losses? Speculations.
On both my WRX and SQ5 the real benefits I experienced came from the torque gains, and with just software upgrades it's an easy and inexpensive thing to do. Spinning to redline for 0-60 times etc are purely academic and for bragging rights. The effortless thrust in the middle-rpm ranges are appreciated.
Safety Car
Joined: Mar 2004
Posts: 4,048
Likes: 1,476
From: South Florida
I know the manual says up to E15 is safe, but in reality E20 is also just fine. The key is to add 2.5 gallons of Pump E85 and then fill up with 91 or 93 octane. This will give you 93-95 octane and be within the limits of the ECU's ability to add fuel VOLUME to make up for the Ethanl. It will take the ECU a little bit of time to adjust the fuel trims. But it will allow the car max timing and pull timing due to knock much less often.
Team Owner
Joined: Jul 2004
Posts: 28,424
Likes: 3,276
From: Hartford WI
I know the manual says up to E15 is safe, but in reality E20 is also just fine. The key is to add 2.5 gallons of Pump E85 and then fill up with 91 or 93 octane. This will give you 93-95 octane and be within the limits of the ECU's ability to add fuel VOLUME to make up for the Ethanl. It will take the ECU a little bit of time to adjust the fuel trims. But it will allow the car max timing and pull timing due to knock much less often.
Safety Car
Joined: Mar 2004
Posts: 4,048
Likes: 1,476
From: South Florida
I've seen it compensate for up to 30% ethanol. But I won't ever recommend that. Say you are running E30 and the ECU adds 25% to the fuel trims to make up for the lambda change and its 70F outside. You are now at the limit of the ECU to add more fuel. A cold front comes in and temps drop to 50F. Now you will be lean and the ECU won't be able to help you.
On the stock tune, you really aren't going to benefit much past E20 anyhow so it's not worth it. I wouldn't bother with more than E20 ish.