I am about to trade my 05 F150 Lariat Supercrew 4X2 on an 08 F150 Lariat Supercrew 4X2. I really like the 18 in wheels and BFG tires on my 05 but the 08 has 20 in wheels with Pirelli Scorpions. If the dealership swaps the wheels and tires with another Lariat on ther lot, what is involved other than swapping them? Does the speedometer or anything else have to be recalibrated? Does the PCM or computer need to be reflashed to let it know I am running 18 instead of 20's?
Are the brakes and rotors the same for the 18 and the 20?
Am I going away from home here? I could have them locate me an 08 with the 18 wheels but other than the 20 in wheels this truck is exactly what I want. I was hoping it would be a matter of swapping them and maybe reflashing the PCM.
What do you guys think? Thanks in advance for your input!

 

OD of the tires are close to the 18's. You shouldn't have to recalibrate as it will be close enough.

 

Not sure if the tire pressure monitor sensors will need to be swapped, in which case, it would be a pain, having to dismount and remount every single tire... may wanna ask about that tho. As far as everything else goes, like FatalErrorz said, if the overall diameter is close between the two, you need not worry. The truck doesn't care how big the rim is, as long as the outside diameter is the same..

 

yep, the 08 has TPMS and the 05 doesn't. the TMPS bands can get expensive. I'd recommend just keeping the 20's on the 08 and putting new rubber on down the road

otherwise, no PCM recal needed if the 05 tires have the same diameter as the 08 tires

 

I maybe did not make myself clear. I am going to have the dealership take a set of new 18's off of a new 08 Lariat on the lot and put them on the new 08 I want to buy that has factory 20 inch wheels now. I am not taking the 18's off of the 05. Would not the TPMS be the same between 2 08's, one 18 and one 20?
If I understand you right they would just take the 18's off of one 08 and put them onto another 08 that has now 20's.
I plugged the tire dimensions into an online calculator and it said it would throw off the speedometer by about 3 mph. It said if I made the swap and did nothing to the speedometer the truck would read 65 but I would actually be going 62. In that case, I think I would want to have the speedometer recalibrated. What is involved in that? Is that the same as reflashing the PCM?
Sorry for the confusion.

 

Give me your 20's, and I'll give you my 18's and recode your puter to read my tpms bands...Just a thought...lol

 

okay, totally misunderstood you

1. Make sure they adjust the invoice price for the 18 vs. 20" rims.
2. The TMPS will need to be updated with the new wheels. Some systems just auto detect the rim bands, but I'm 99% certain Ford has them logged into the ECM.
3. If the Dealership does the swap, they should do any and all ECM adjustments before you recieve a key. Just make it part of the work order before you take ownership. I doubt they'll mind. Especially as the 20" rims are very popular.


4. What size are the 18" and the 20" you're looking at? They should be the same size...unless you're trying to grab the 20" rims off a 4x4 truck.

5. I personally would grab the 20's. They look better to me, and 18" rims are expensive when you're buying rubber, and for some reason it seems 20" are cheaper. Maybe it's in my head.

 

I feel kind of stupid for insisting on the 18's. I just like the way the 18 in rims look (or maybe more I do not especially like the 20's). Also, the 18's I have right now ride great and I have heard that the Pirelli 20's ride rough.

 

I've heard good and bad about the Pirelli tires. They are better than the Daytons/Continentals though

you've got to remember though that with a 20" rim, there is maybe 4-5" of sidewall to support a 4,500+ lb truck. vs the 18" rims with their extra bit of sidewall.

For me I'm also thinking about the way the 20"s look with bigger tires (I'm hoping to upgrade when I need new rubber). The 20's fill the wheel well and look more proportional with 35" tires IMO. I'm not a fan of the huge rubber/tiny rim look. Kinda looks weird to me, and it's scary with all that sidewall flex

 

I know where you're coming from, I think you're another person that likes the look of more sidewall less rim...

the 20s start looking ok at about 37" tires...

like tylus said, make sure they handle the tpms stuff and you should be good.

 

Yep, it's an easy update...We had a guy replace one the tire shop broke (no clue how they managed that) and we updated his. Took 5 minutes.

 

What exactly is involved with the TPMS? As long as both trucks are Lariats and one has 18's and one has 20's and they are both 2WD, would they not both have the TPMS? And if so, what besides taking the wheels off of one truck and putting them on another is involved?

 

They are coded individually to the vehicle...The dealer can fix it for you on the spot.

 

the tpms is on the rim, it's an rf device that transmits the tire pressure to the computer. the computer has to know which tpms it's talking to, otherwise it would get input from any f150 around you (theoretically speaking). take the wheels away without touching the computer = your computer won't sense the sensors in it's wheels anymore.

 

And your dash will show a TPMS light, 24/7 until you reinstall. UNLESS you reprogram the PROM. (aka PCM, or ECM) Wanna' bet me?