New Cooper Tires - MPG Help

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06-10-2018, 08:38 AM

#21

jol

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Quote:

Originally Posted by Pristine1

Jol, is that on the lie o meter or hand calculated? Do you have the 10 spd? All brands will have slightly different measurements. So you may have gained some width not knowing it. Still your loss sounds about what someone on 35's would be getting. I get about 21 mpg highway after a 2 inch lift and 2 inch larger tires. I got the biggest tire you could get with out going to a heavy LT tire. Yet I gained 500 lbs per tire load capacity over my stock tires. People never pay attention enough to load capacity. Each tire will vary depending on its purpose.

No sir that is not using the "Lie-O-Meter" like that calling it what it is. I use an app called fuel up and basically use it every time showing. I know what you mean those are not very accurate usually on high side. It is a 6 speed I know what you mean about the width it is a bit wider than the original tires. Height is about the same maybe a half an inch, shows tread as 9" wide and 32.1 high, and seems that is what the others were also.. Hey it is a truck and I had these tires on a 2008 F150 5.4 after removing Goodyears it had on it they were also P tires and that is what this new truck had. Person I sold it to had no problem switching out the tires so that was a good thing.

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06-10-2018, 09:50 AM

#22

tradosaurus

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1st Ecoboost owner that isn't claiming to get 22+mpg.

You went from a 17" tire to an 18" tire. I did the same thing and my speedometer is off 4 -5 mph. If the speedometer is reading 70 mph I'm actually going 75 mph.

My understanding with the "Eco"boost engines is that above 70 mph your mpg goes down dramatically. I'm wondering if you are just going faster than the speedometer is reading and therefore throwing your mpg readout off?

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06-10-2018, 10:14 AM

#23

Siber Express

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When I went from the Bridgestone 275/55 20 to the Cooper Discover HT Plus 305/50 20 on the stock wheels I lost 2 MPG on average, wider tire, stickier rubber=less mileage.

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11-26-2021, 12:09 AM

#24

ThirdCoastElectronic

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Quote:

Originally Posted by cboughn

Thanks everyone for your responses. Quick question - where would you recommend I go/visit to recalibrate the speedo? Is it something I should take to the ford dealership, or...?

dealership or you can do it yourself with a ELM obd to USB adapter and a laptop. Click on programming tab and go to BCM and you can enter new values for tire/rim size. That way your speed and mpg display with be corrected.