A few months ago I installed some long tube headers and had my car tuned for 93/E85. I’ve heard all the talk about how E85 dilutes engine oil and breaks it down much faster than normal pump gas. I won’t pretend to act like I know the chemistry and beyond of how they interact because I don’t. My question is, with the addition of E85 is it necessary to go up a grade (from XW-30) and stay with XW-40? I have been using QS 5W-40 and I know it’s an excellent oil. I recently obtained a fair amount of 10W-30 on clearance and would like to throw that in there for my typical 5K OCI. Also does my OCI need to be reduced at all? Car is daily driven, trip to work is 25 miles one way, doesn’t get short tripped much at all. Thank you!
Tuned 5.0 Mustang GT & E85
- Thread starter MrCoyote
- Start date
My son has a 2020 GT PP1 A10 and stock for now.
I would definitely run all that 10w30 and change at 5K miles.
Once all that oil is used up XW-40 will be fine.
What year is your coyote and the mods ?
These 4 cam, 32 valve engines purr like a kitten at 7500 RPMs and tuned on E85.
Yes, do UOA to see how the oil (and wear) is at 5K with E85.
I would definitely run all that 10w30 and change at 5K miles.
Once all that oil is used up XW-40 will be fine.
What year is your coyote and the mods ?
These 4 cam, 32 valve engines purr like a kitten at 7500 RPMs and tuned on E85.
Yes, do UOA to see how the oil (and wear) is at 5K with E85.
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Not a bad idea
2021. Catted long tube headers, MGW short throw shifter, E85/93 tune.
MGW is hands down the best shifter on the market. I absolutely love mine.
No, that’s the one thing I regret is not doing a before and after dyno. But from most stuff I’ve seen, with my mods I should be making around 470-480whp. Stock Gen 3 5.0’s usually dyno around 390-400whp. As far as tuning I went with Wengerd Performance in TN. Can’t speak highly enough of him and he’s gaining a lot of popularity in the S550 community. I’ve heard PBD has gone downhill since Rob Shoemaker left, but again thats just hearsay.
Same. I got the flat stick X spec and it’s night and day difference. I still get 3rd and 4th gear lockout. That’s the one thing I hate about the car, the MT-82 isn’t the greatest transmission. Wish they would option the Tremec 3160 or even 6060 in the GTs. I’d pay a few grand extra for one.
Getting your engine to at least 174 degrees will allow the alcohol to burn off and help keep the oil clean. If you're running E85 full time, shorten the OCIs
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