New Tires - Nokian Outpost APT

[Hot Runr Guy]

UPDATE: I've put about 2,000 miles on these tires so far. The biggest thing I've noticed is a drop in average MPG. My average MPG has been declining ever since I got these tires, while my driving routines are staying the same. I'm averaging around ~22 mpg city and ~31 mpg highway, roughly ~26 mpg average. With the factory tires I was sitting at around ~27.5 mpg average. So a slight drop overall. I have a roughly 1000 mile trip planned at the end of May so we'll see how they perform MPG-wise during that trip. Besides that they've performed great in the little bit of rain we had back in March and have done well driving on gravel roads in the hills.

You mentioned in your original post that you did not adjust the odometer/speedometer to compensate for the larger OD tires, so just how are you accurately calculating your mpg?

HRG

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[Triangle6887]

You mentioned in your original post that you did not adjust the odometer/speedometer to compensate for the larger OD tires, so just how are you accurately calculating your mpg?

HRG

The MPG calculator on the truck has remained mostly accurate. The first few fill ups I calculated the MPG myself and found it was within .5 mpg of what the dashboard reported. The dashboard calculator is known to slightly overestimate MPG by 3-5%. I've read of people adjust the vehicle's MPG calculator fix that overestimation. Since I found the dash was still relatively accurate, I have not gone forward with adjusting the fuel system's AFE bias. During my last oil change I asked the dealer if they could adjust the computer to account for the wheels being slightly bigger and they said that Ford forbids them from doing so.

Regardless, the new tires didn't increase in size all that much. Maybe a half inch of total width at most. Based on the online calculators I've found, my speedometer is still accurate within about 1 mph until I exceed 60. Once I exceed 60 mph the difference is between 2 and 2.5 mph. Most of my driving is under 55 so the difference in the speedometer reading would be negligible.

 

[Cancunbadlands]

Seen a lost on MPG is normal with a bigger tire size upgrade

 

[Hot Runr Guy]

The MPG calculator on the truck has remained mostly accurate. The first few fill ups I calculated the MPG myself and found it was within .5 mpg of what the dashboard reported. The dashboard calculator is known to slightly overestimate MPG by 3-5%. I've read of people adjust the vehicle's MPG calculator fix that overestimation. Since I found the dash was still relatively accurate, I have not gone forward with adjusting the fuel system's AFE bias. During my last oil change I asked the dealer if they could adjust the computer to account for the wheels being slightly bigger and they said that Ford forbids them from doing so.

Regardless, the new tires didn't increase in size all that much. Maybe a half inch of total width at most. Based on the online calculators I've found, my speedometer is still accurate within about 1 mph until I exceed 60. Once I exceed 60 mph the difference is between 2 and 2.5 mph. Most of my driving is under 55 so the difference in the speedometer reading would be negligible.

I'm not talking about adjusting the AFE, I'm talking about adjusting the ODOMETER so that the distance you travel is accurate. There is a 3.5% difference in circumference (the distance your tire travels with each revolution), so in reality, your 1000 mile test drive will really be 1035 miles. You can confirm this if you have a independent GPS that you can use to confirm the distance traveled vs what your odometer says.

HRG

 

[Triangle6887]

I'm not talking about adjusting the AFE, I'm talking about adjusting the ODOMETER so that the distance you travel is accurate.

As I said, I asked the Ford dealer who does my oil changes about adjusting the tire size in the computer and they told me that Ford corporate forbids them from doing so. However, I know you can use FORSCAN to adjust the body control module. That is on my to-do list but I'm told that doing so will void my warranty. I need to do more research on the matter before I decide.

 

[Triangle6887]

Just completed a roughly 600 mile roundtrip to Idaho for some firearms training through my work. I began by departing Pendleton, Oregon on Highway 395 south to John Day, I then traveled east on 26 through Nyssa, settling on the far east end of Boise that evening. When I filled up at the gas station by my hotel I saw that it clocked 316 miles and an average of 30.9 mpg.

However, like @Hot Runr Guy pointed out this is incorrect because of the larger Nokian tires I have on the truck. Assuming the 3.5% number is correct for difference in tire size, my miles driven would've been 327. I didn't think to check how much fuel I filled up with, but knowing everything is off by 3.5% we can assume its approximately 1.08 mpg plus or minus (29.8 - 31.9 mpg).

The return trip home was not fun. I took I-84 all the way back from Boise. If you've never done that drive you can check Google Maps to see that 84 cuts through the Blue Mountains. Boise sits at about 2,700 ft in elevation. As you travel east you gradually gain elevation; hitting 3,451 ft at Baker City. You dip back down to La Grande at just shy of 2,800 ft. You then start gaining elevation again until you summit the Blues at 4,193 ft before hitting a 6% grade on Deadman's Pass (aptly named because of the insane number of wrecks on this stretch of 84 during winter). You plummet 2,000 feet in just 6 miles and when you hit Pendleton you're at 1,100 ft in elevation. The whole time during this drive I was fighting eastward winds that were blowing my truck around and making the journey unrelenting. I really felt as if the little 2 liter EcoBoost motor really struggled to maintain the 73 mph pace on this 3 hour drive.

If we run the calculation again, my odometer should've read 220 miles. Again, I was a buffoon and didn't check the amount of gas I pumped because I was spent from this trip and ready to be home. Including the correction for MPG it should be sitting somewhere in the range of 24.7 - 26.5.

This trip really made me question if this truck is for me. I don't know why but it felt cramped in the driver seat and the motor felt esspecially gutless on the return trip. I don't think this is an issue with the tires but more an issue with the platform itself. On the bright side, I had never driven 395 all the way to John Day and I have to say that it is an extremely pretty drive - esspecially through the Battle Mountain and the Ukiah-Dale Scenic Corridor. I highly recommend that route for anyone passing through the area!

 

[Mudduck]

Some seat jackers may help you to feel more comfortable. I made my own aluminum spacers to raise the front of the seat 1". I don't feel like I'm leaning forward while driving anymore.

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