Powerboost Livernois tune with 34-35" tires

[Jmitchelltfo]

Any feedback from Livernois customers who run larger than stock tires?

I took a decent hit on the MPG's on the interstate, and I'm not certain if my pickup is just recalibrating for the bigger tires (they are only 8 pounds heavier per corner compared to my OEM 20's). But it was a noticeable drop on the interstate. I can still get 23 MPG around town, which isn't terrible, but I'd obviously like to see an improvement if possible.

I understand I will never see 30+ like some of you......but 26-27 shouldn't be impossible since I'm running a very conservative offset and lift.

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[v8440]

Has the truck been recalibrated to account for the taller tires? If not, you're getting better mileage than calculated unless you're basing your mileage on a calculation done that got the mileage from a gps.

 

[Jmitchelltfo]

Has the truck been recalibrated to account for the taller tires? If not, you're getting better mileage than calculated unless you're basing your mileage on a calculation done that got the mileage from a gps.

I haven't done any forscan work yet. I still need to order the dongle.....I procrastinated since I didn't want to learn a new APP....lol.

The GPS speed compared to the displayed speed is only about 1 mph difference at 70 mph.....so I can't imagine that the hand calculated fuel mileage will be wildly different than what the dash shows. I'll check it anyway, like I always do.

 

[v8440]

Yeah, likely it won't matter much in that case. I'm surprised it's only a mph or so at 70.

 

[Jmitchelltfo]

Yeah, likely it won't matter much in that case. I'm surprised it's only a mph or so at 70.

According to Waze………I haven’t run any other apps to confirm speed, but Waze has shown 1 and sometimes 2 mph discrepancies

 

[22Platinum]

According to Waze………I haven’t run any other apps to confirm speed, but Waze has shown 1 and sometimes 2 mph discrepancies

I went from stock 275/60/20 to 325/55/22 (35"x13.50") and the speedo was only off 2mph at 70
But I also lifted 6"
And not powerboost

Around town I'm getting 16mph and I'm hopeful for 18mpg highway though I haven't had a true shot at that yet.

I got 15mpg towing 1500lbs @ 68mph over 1400 miles, which I thought was reasonable; same trip I found 20ish MPG at 55mph and 12mpg at 80mph.

 

[Ziggy73]

I've heard a two MPG difference negative just by removing the front air dam, that's essentially what you have done with the level, so add that in with the small weight difference and you're probably about right. The recalibration will help a little.

 

[Coll4646]

According to Waze………I haven’t run any other apps to confirm speed, but Waze has shown 1 and sometimes 2 mph discrepancies

Make sure your phone isn’t connected to CarPlay or anything else. Put 295/65/20’s on mine, checked a speedometer app and it I thought it was weird that the speed was barely off. Turns out the app was pulling the speed from the car vs gps, the difference in the two was just the delay. I disconnected everything and the speed difference was a decent bit more lol

 

[Jmitchelltfo]

Make sure your phone isn’t connected to CarPlay or anything else. Put 295/65/20’s on mine, checked a speedometer app and it I thought it was weird that the speed was barely off. Turns out the app was pulling the speed from the car vs gps, the difference in the two was just the delay. I disconnected everything and the speed difference was a decent bit more lol

Ok, well......I'm always connected to carplay. I will definitely give that a shot. Doing the math on the difference in the tire size it should be around a 3 mph difference.....but I am from the Ozarks, so my math could be completely wrong. I'll give it a shot and see what happens.

 

[SilverSpur]

I ran 17X40's on my old 74 chevy 2/4T PU. There is a lot of rolling resistance with wider tires. That truck was running a 4:10 Eaton locker so gearing improved MPG. It had a small block 400, 4 bolt mains, a cam built for the highest lift and duration before having to install solid lifters. a Carter AFB Superquad 650CFM, 4 BBL, and a Edelbrock high rise intake. Couldn't dyno back then but I would race Harleys and beat them. It could smoke the rear 40's and slide the truck sideways. For the speedometer error, I found it was off by 5 mph for every inch of tire height difference increase. Back then we had to change the speedo drive gear in the transmission.

 

[Suns_PSD]

Physics, says that your lifted F150 isn't going to ever get 25+ mpg.

Mine is heavy with 22" wheels (that's a huge hit) but I average right at 19 mpg most tanks, and see a little better (20ish) when I drive slowly outside of my Hill Country home.

It is what it is, and I do care about economy.

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