[srt8dodgeboy]

I'd like to upgrade my SXT wheels to the factory 20" wheel/tire package. However, the 20" set has a slightly larger overall diameter than the 17" set. Has anyone on the board made this upgrade (specifically to the factory 20" wheel/tire size)? If so, did you notice any loss in performance or gas mileage?

I really like the look of the 20" wheels, but am not willing to sacrifice much in the power or economy department.

Thanks in advance...

Dave

 

[RobsNitro]

OK I have the SLT 4x4... And I had the 17" factory rims and when I upgraded to the 22"'s that I have now i lost almost 2mpg and the 22" with a 265/35 tire only adds about 1-1.5"s to the height.

 

[srt8dodgeboy]

That's good to know... It looks like the factory 20" option adds about 0.6" to the overall diameter. Hopefully it will be 1mpg or less...

 

[RobsNitro]

That's good to know... It looks like the factory 20" option adds about 0.6" to the overall diameter. Hopefully it will be 1mpg or less...

not a problem.. hopefully it works out for ya!

 

[NitroCharger]

OK I have the SLT 4x4... And I had the 17" factory rims and when I upgraded to the 22"'s that I have now i lost almost 2mpg and the 22" with a 265/35 tire only adds about 1-1.5"s to the height.

My SC tuner lets me adjust this for my Charger but I'm new to the Nitros and I don't know if the tuner exist for the Nitro yet. Did you
adjust the speedo calibration for the larger size? If you didn't your speedo will read slower and less mileage than your actually doing.
This would lower your mpg calculation (manual or EVIC) to lower than it actually is, but I'm sure there's gotta be some loss.

 

[fcsallan]

The other option is not to go with the factory tire size. If you go with a slightly narrower sidewall, you will maintain the same ride height and you won't lose anything.

 

[srt8dodgeboy]

The other option is not to go with the factory tire size. If you go with a slightly narrower sidewall, you will maintain the same ride height and you won't lose anything.

I agree... Unfortunately, the perfect size is a 255/45/20, and there are like 4 tires made in that size. None of which are really appropriate for this application.

Dave

 

[RobsNitro]

No.. for 2 reasons

1) I dont have access or the know how to do what you just said.

2) I wanna say the actual difference was only 1.3in's ??.. wont swear to it but i really didnt think it would be off by much which it isnt anyhow really. So i wasnt too concerned but if you got an idea for me to test it please let me know! lol

p.s. there are no speedo shops around here..

My SC tuner lets me adjust this for my Charger but I'm new to the Nitros and I don't know if the tuner exist for the Nitro yet. Did you
adjust the speedo calibration for the larger size? If you didn't your speedo will read slower and less mileage than your actually doing.
This would lower your mpg calculation (manual or EVIC) to lower than it actually is, but I'm sure there's gotta be some loss.

 

[srt8dodgeboy]

No.. for 2 reasons

1) I dont have access or the know how to do what you just said.

2) I wanna say the actual difference was only 1.3in's ??.. wont swear to it but i really didnt think it would be off by much which it isnt anyhow really. So i wasnt too concerned but if you got an idea for me to test it please let me know! lol

p.s. there are no speedo shops around here..

I just did the math on your 22" tires... The difference between them and stock is actually less significant than the factory 20" and factory 17"!

If you had 235/65/17s stock, and now have 265/35/22s, your diameter increased by only 0.3". That means you are actually travelling 60.6mph when your speedo reads 60mph (big deal!). You probably lost the mpg simply due to the increased rotating mass of the 22" wheels. Are they steel or aluminum? Do you know what the weight difference was from stock? I'm betting it was very significant.

Anyway, that doesn't bode well for me with my 20" factory upgrade. My tires will be taller than yours and I will also increase my rotating mass. I'd have the potential to lose even more mpg. Ugh...

Dave

 

[RobsNitro]

Wow that is interesting.... Les Schwabb is who I went through for the tires they must have done their math wrong possibly?

I just did the math on your 22" tires... The difference between them and stock is actually less significant than the factory 20" and factory 17"!

If you had 235/65/17s stock, and now have 265/35/22s, your diameter increased by only 0.3". That means you are actually travelling 60.6mph when your speedo reads 60mph (big deal!). You probably lost the mpg simply due to the increased rotating mass of the 22" wheels. Are they steel or aluminum? Do you know what the weight difference was from stock? I'm betting it was very significant.

Anyway, that doesn't bode well for me with my 20" factory upgrade. My tires will be taller than yours and I will also increase my rotating mass. I'd have the potential to lose even more mpg. Ugh...

Dave

 

[NitroCharger]

Yeah, .3 looks right, not much of a difference to worry about it. At 1.5" it
would have been a little more significant.

Here's a link to tire size calculator.

http://www.miata.net/garage/tirecalc.html

 

[niftie]

The factory 17's and 20's are almost identical in o.d.
I ran the 17's in the winter and you're within about 1mpg.
The 20's look waaaaay better and I think they drive nicer too.
So I say go for it!!

 

[srt8dodgeboy]

The factory 17's and 20's are almost identical in o.d.
I ran the 17's in the winter and you're within about 1mpg.
The 20's look waaaaay better and I think they drive nicer too.
So I say go for it!!

That's the kind of feedback I was hoping to hear. Thanks! I think I'm going to do it.

Did you drive with Wrangler HPs in the winter? How did they do? Were they the 20" or 17" HPs? I have HPs on my 17", and that's what'll be coming on the 20" as well. I kind of wish they were different treads, so I could compare. This vehicle is my primary winter and secondary summer driver.

Dave

 

[niftie]

I'm glad it helped. Go for it! The truck sits nice and handles better with the 20's.
Now for the harsh reality, and it's only my opinion so don't flame me.
Yes, the 17's were the factory Goodyears and in my opinion, they SUCK as a winter tire! They are tolerable in the snow and dry but NFG in the rain or ice.
Mind you, if your winters are mild you may get by, but I head way up North to go snowmobiling every weekend.
I left them on last winter because I was tight on cash but even the frugal Mrs.Niftie told me to start saving my pennies so we can get dedicated snowtires for the 17's for the coming winter.

That's the kind of feedback I was hoping to hear. Thanks! I think I'm going to do it.

Did you drive with Wrangler HPs in the winter? How did they do? Were they the 20" or 17" HPs? I have HPs on my 17", and that's what'll be coming on the 20" as well. I kind of wish they were different treads, so I could compare. This vehicle is my primary winter and secondary summer driver.

Dave

 

[kevinmoire]

Something's going on here

 

[jimbo1102]

20"s

:wavey:
G'Day!
Don't know much about tires, but I got the 20"s (factory stock).:Na_Na_Na_Na:
I find the ride very smooth with them, and my lowest km/L to date was 10.2, highest 14.6 km/L.
They even have NITROgen in them! :rockon:
Little green valve caps .....:rofl:
AND ...... they sure make my NITRO look puuuurrrrrrrdy!!:Racing:

SO GO FOR IT, EH! :smileup: Make your NITRO look puuuurrrrrrrdy too!:chuckle:

:thk:
Though I am looking to get steel winter rims and rubber.
Dealer parts guy calculated that I could put 16"s on it with some BIGGER rubber?:SHOCKED:

 

[DrewsBrews]

Yes, I believe early SXTs and the later SE had 16"s as a base option. Most of the 08+ liberties (based on the nitro chassis/drivetrain) have pretty decent looking 16"s that will fit also.

I think I remember Scar0 had some steel 15"s that he test fitted. They technically fit but so close that the tiniest pebble would get smashed between the wheel and caliper.