Went from 18" to 20" Questions

[HydrogenCyanide]

I have a 2014 SLT. I've had the SLT 18" wheels with the Goodyear Assurance CS tires (P265 65 R18)since I bought that truck in January. I have always loved the look of the 20" chrome wheels that come in the upgraded SLT package.

 

I bought a set off of ebay that had been driver for 3000 miles. They came with the Continental Cross Contacts (P275 55 R20). They are in almost perfect condition. They came with TPS sensors and my local tire shop did a road force balance. The trucks rides as good (maybe better) then it did with the original 18's.

 

Now for my questions.

1. I thought the diameter of the tire would be the same as they are both factory. It is definitely not the case. Standing side be side it seems like the new tires stand a quarter and to a half an inch taller. Should I be going to dealer to have something recalibrated or is the difference too small?
2. Might be in my head, but the truck seems a little more sluggish with a rougher shift when going at slow speeds at shifting from 1st to 2nd. Could this be due to my first question? It's not major but I think it is a little different. Seems to be getting better mileage according to the DIC but I have only driver about 30 miles since the new set has been on.
3. I always have switched winters and summers on my other car. I could relearn the TPMS's be simply letting air out tires in the correct order. The manual in the truck references some sort of tool. Do you really need the tool? Is there another way to pair the sensors and the truck?

Thanks for any help.

 

BTW.....love the look of the wheels and tires. Just makes the truck stand out compared to before.

 

[Chris]

They did away with the letting air out method in 2009 or 2010. As for diameter, they are close enough. My truck has 275/55R20 and my spare is a 265/70R17.

[fondupot]

the 20's might be a bit heavier, but they are basically the same diameter. The extra weight and slightly extra width might cause a bit of "sluggishness" as you describe, but my guess is most of it is in your head. no offense.

 

 

[HydrogenCyanide]

No offense taken. I kind of suspected that.

 

I take it there is no way around this re-learn tool?

[Last C5]

No offense taken. I kind of suspected that.

 

I take it there is no way around this re-learn tool?

I suspect the relearn tool is about the same that we've been using on the Corvettes since 2006. What will soon be sorted out by this forum is which tool works the best. The aftermarket will offer several different tools but some won't do the job as well. We'll see.

[cmpcpro]

The dealer uses a little tool you put the truck in learn mode from dic then put tool to each tire. Horn honks at each tire

[SLESierra]

I would give the relearn a try remove all the valve caps first and give it a shot what can it hurt you will know with the first step if you need the tool. Turn the ignition to run without the engine running. Press and hold the LOCK and UNLOCK buttons on the key fob at the same time. Horn will honk twice and the message relearn mode will appear. With a ball point pen I released air from the drivers side front tire (about 7-8 pounds) until the horn chirps. The air release must be continuous until the horn chirps. Move to the passenger front, Passenger rear and the drivers rear repeating the same air release with the ball point until the horn chirps at each tire. The horn should also chirp twice at the driver's rear tire when all positions are learned. Turn off the ignition and start the vehicle. Warning lights and Message should be gone and all 4 TPS should be learned and functioning in the correct position.

[cmpcpro]

Not sure about the unlock and lock buttons I went into dic and to tps screen and held middle button and it went into learn mode

[thewhitestallion]

on the 14's the unlock and lock button method is no longer the way to do it. you have to go into the dic and go to your tire pressures and click the right arrow and then it will ask you if you want to relearn your sensors and then you just hit ok and it puts the truck in learn mode. also cool thing about these trucks if you cant remember to start with the left front and work clockwise around the vehicle just look at the turn signals, which ever turn signal is lit up that is the tire to "relearn".

[HydrogenCyanide]

It is very easy to put the truck in learning mode but letting air out of the tire definitely does not work. My local tire shop had the tool and did it for free. Loving the new look with SLT wheels.

 

Before

 

After