Have a new 2018 SXT AWD with standard 265/60/18 tires/rims. I switched them out to 265/50/20 tires/rims (rims are Dodge 20 you get on GT models, tires Pirelli I think you get on Jeep. Since installing them (tire place did it) At 70 mph I feel a stutter, or jerk, like the truck is being held back, or a hard shift (even though it's already shifted into 8 well before). I can still give it gas and it will go but there is something happening. I don't notice it any any other speeds. Am I missing something with upgrading wheels? These should work fine. Would changing tires mess up maybe AWD system? Any help, before I go to dealer would be helpful.

 

Check tire sizes. All four need to be the EXACT same size, else you will break stuff.

Also, some of the newer ones get really offended when tire size changes, and you don't tell them.......

 

Yes all 4 are same (new)

 

Make sure tires are balanced + alignment right.

 

Tires are balanced and pretty sure alignment is not the issue. Seems to come from engine or transmission.

 

Is this the V6 model? The static mass of the wheel and tire combo (likely a bit heavier) in addition to increased drag above 70 mph is likely causing your transmission to downshift as it tries to overcome these factors. At 60 true mph, your speedometer will be reading just over 2mph faster.

If this is a HEMI mated to an 8 speed, then my above ideas remain, but I'd be surprised that it would cause a dowshift and lurch.

 

It is a V6 and there is probably an added weight to the tires/rims (larger rims) but then would another person in the vehicle cause the same outcome?

 

GT is a v6 and they come with those wheels so I doubt it's a weight thing.

 

Does the yellow traction control light come on when this is happening? I'd bring this up to the dealer, there might be a software reset or upgrade they can try. If it is predictable, you might want to get a video of it to show the tech.

 

Nope no light. Thanks for a possible solution.