I have a 2012 CC 4X4 6.2L short bed w/3.73 gears. It now has 275-65-18 tires. I have a chance at a NTO set of 275-65-20 wheels and tires from a 2016. They are a couple inches taller, which translates to roughly 6" more in circumference. I have a few questions.


Will I see better gas mileage?
Will there be a significant power drop?
Can I just bolt them on with no issues, clearance or otherwise?
Will TPMS work with no issues?


Other than obviously throwing the speedo off, am I missing anything?


FWIW, it will never tow, just occasional hauling.

 

almost ZERO difference.. may add 1 mph per speedometer error...


less then 2 percent difference in size.

 

The circumference is about 6.25% more on the 20" tire (100.8 vs 107.1). Wouldn't that make the speedometer 6.25% off? I would think that when the speedo is reading 60 MPH I would actually be doing 63.75...right?

 

Not so sure about that.






Tire 1
275 / 65R18

Tire 2
275 /65R20

(285/75R16 or 33X12.50R15)
Compare Tire Sizes Visualizer

Tire Specs
Tire 1 Tire 2
Diameter
32.1

34.1

+6.2%
Width
10.83

10.83

0%
Sidewall
7.04

7.04

0%
Circumference
100.7

107

+6.3%
Revs/Mile
629.1

592.2

+6.2%

All Specs are in Inches.
Speed Difference
Tire 1 Tire 2
20 mph
21.2

30 mph
31.9

40 mph
42.5

50 mph
53.1

60 mph
63.7

70 mph
74.4

80 mph
85

90 mph
95.6

 

i went from oem 16 to oem 18 to oem 20 on a 99 V10 with 4:30 and didnt notice any change in performance until i put the 16's back on a few years later to sell and truck felt faster off the line
still love the look of the 275/65/20 over the smaller OEM combos and to me it outweighs any slight change in performance

 

Any thoughts on mileage, TPMS?

 

I finally put on the new wheels I bought. Of course, I have a "Low tire pressure" message. Do I need to do anything with that, or will the truck eventually recognize the sensors and that message goes away?

 

I did the same with no issues, maybe a bad tpms sensor?

Looks good!

 

I made the same switch from the stock 18" to the factory polished aluminum wheels and there is nothing that neds to be done other than bolt them on and enjoy. I didn't loose anything I didn't gain anything other than a better looking wheel. I did however reuse my old tpms setup from my original wheels.

 

Did you do the tpms reset? It's in your owners manual, but I believe you turn the key on, turn the flasher on and off 3 times and the horn will honk. Let air out of the left front until horn honks, go to right front and repeat, then right rear, then left rear. Message center should say training complete. Light should go out.

 

To resolve your issues, simply have someone with access to a Ford IDS scan tool connected to it, and perform what's called tire size/axle ratio parameter change under the "programmable parameters" sub-menu of the module programming selection. Since that tire size combo is an existing factory option, simply select that tire size in the menu selection of available tire sizes, and reprogram that into your PCM calibration. This will resolve any minor issue with speedometer inaccuracy, ABS, transmission shift points etc.

 

Keep us posted on your power and mpg changes. I had those same wheels on my '14, it looks great.

 

Hey m-chan, how come my local dealer can't do the reprogram on my new 2017?

 

Because yours is a 2017 model year. They likely use the more expensive style TPMS sensors is one reason I would suspect. The other being, that FoMoCo in their infinite wisdom does not give us techs at the dealer level access to make such changes via our scan tools on newer models that are likely way more advanced in how all the modules "talk to" each other via networks. A couple of us have already ran into this issue and consulted with Ford Hot Line for assistance only to receive the response that "newer model year vehicles do not support changes in wheel/tire size and/or axle ratio changes.

This makes summer and winter tire changeovers in geographical areas that mandate as such, a nightmare when making switchovers where the tire sizes are different between the two.

On my own personal 2016 F-250 CCSB 6.7L 4x4 truck that came ordered from the factory optioned with LT275/65R20 wheels, I make the switch every winter to the set of LT275/70R18 snow tires on steel rims I keep for those months. When I do this, I also use my own IDS and do the programmable parameter recalibration as well, ensuring correct speedometer reading and odometer mileage accumulation all year round. On my particular vehicle however, it is still just a carryover of the exact same setup used since 2011, just before release of the current all new 2017 body style.

 

That's pretty much how they put it to me. But they also said since the 2016 SD they have not been able to change sizes. However, I have read others were able to change the tire size programming. Thanks.