Cooper discovery at3 4s 275/60-20 installed.

[Franky350]

Its 4 mph at 70. Dash says 70 but real speed as calculated by gps radar detector is 74.

I am about to order the Coopers you got. Did you feel the need to recalibrate your speedometer with the slight height increase?

 

[rah6887]

I am about to order the Coopers you got. Did you feel the need to recalibrate your speedometer with the slight height increase?

No I did not, with that being said, I did ask the dealer about recalibration, I was told that they cannot do it on the 5th gens.
But it wasn't that bad
50mph - actual 51
60mph - actual 62
70mph - actual 73
And so on...

 

[dwalme]

I am about to order the Coopers you got. Did you feel the need to recalibrate your speedometer with the slight height increase?

You can use Alfaobd $50, SGW bypass cable $25, Bluetooth obdii adapter $10 and your Android phone/tablet to change your tire size.

I think it’s well worth it.

 

[Franky350]

No I did not, with that being said, I did ask the dealer about recalibration, I was told that they cannot do it on the 5th gens.
But it wasn't that bad
50mph - actual 51
60mph - actual 62
70mph - actual 73
And so on...

Thank you! That reaffirms what I thought about going from 275/55 to 60. I did not really worry about it but then read about shift point issues and so on on here. I myself upgraded the tires on our Chrysler 300c, because of wheel failures due 45 tires, going a little higher. No issues beside a certain speedometer difference.

 

[Franky350]

You can use Alfaobd $50, SGW bypass cable $25, Bluetooth obdii adapter $10 and your Android phone/tablet to change your tire size.

I think it’s well worth it

Thank you, I appreciate that. I will see how it goes once we have the tires.

 

[NJC1684]

I am about to order the Coopers you got. Did you feel the need to recalibrate your speedometer with the slight height increase?

test against a gps app once installed and then decide if it’s worth it to you. I used the Rough Country calibrator for peace of mind.

 

[Billy James]

I am about to order the Coopers you got. Did you feel the need to recalibrate your speedometer with the slight height increase?

I don't have Coopers. I do have Pirelli Scorpion All Terrain Plus 275/60R20. I felt the need to calibrate. I was off 2 mph at 50 and 3 mph off at 60. The MPH difference wasn't that bad; but there are other things it affects. First, the transmission shifting seemed to change...and not for the better. Second, the MPG calculations dropped by 2.5 MPG. I bought the Rough Country calibrator for $139 and it took about 15 minutes to get everything right. Now, my speed is dead on with GPS, the transmission shifts normally again, and I am getting accurate MPG calculations again. The $139 for calibrator and the little bit of time it took to do it are well worth it.

 

[Franky350]

test against a gps app once installed and then decide if it’s worth it to you. I used the Rough Country calibrator for peace of mind.

I read about other problems after recalibration, like parking sensors and distance control not working anymore. Can you report that?

 

[Franky350]

I don't have Coopers. I do have Pirelli Scorpion All Terrain Plus 275/60R20. I felt the need to calibrate. I was off 2 mph at 50 and 3 mph off at 60. The MPH difference wasn't that bad; but there are other things it affects. First, the transmission shifting seemed to change...and not for the better. Second, the MPG calculations dropped by 2.5 MPG. I bought the Rough Country calibrator for $139 and it took about 15 minutes to get everything right. Now, my speed is dead on with GPS, the transmission shifts normally again, and I am getting accurate MPG calculations again. The $139 for calibrator and the little bit of time it took to do it are well worth it.

Yeah I am worried about that. I read about other problems after recalibration, like parking sensors and distance control not working anymore. Can you report that?

 

[NJC1684]

I read about other problems after recalibration, like parking sensors and distance control not working anymore. Can you report that?

I’m not having any issues.

 

[Billy James]

Yeah I am worried about that. I read about other problems after recalibration, like parking sensors and distance control not working anymore. Can you report that?

No problems since I calibrated.

 

[Franky350]

No problems since I calibrated.

Thank you!

 

[Franky350]

I’m not having any issues.

Thank you!

 

[A-TEAM]

So I’ve added 10k miles of mixed driving on these tires and so far so good. The tires don’t even look like they’ve worn any rubber away yet, and I towed a 6k lb camper around a couple times a month over summer. I haven’t recalibrated anything and haven’t noticed any shifting issues or anything like that. I have the 3.21 gears though. I still just use my uniden r3 for speed. Truck is at 16k miles now and still has not been back to the dealership since the day I drove it off the lot. I do my own oil changes (on its fifth change already) and run 89 octane fuel. I’ve been averaging 20-22mpg highway. Going to rotate the tires here very soon.