New Wheels/Tires Speedo Surprise !

asautt

Original poster
Member
Dec 5, 2011
40
We changed out the stock wheels/tires on my wifes TB to 275/45R20s a week ago. According to a couple of tire size calculators the new combo is somewhat larger diameter than the stock setup. "Should" see a 3 to 4 mph difference at 70 mph. Finally got out on the highway yesterday with the GPS so I could tell her how much slower to drive to be safely at the speed limit. Was very surprised to find the speedo speed matches GPS speed EXACTLY at all speeds up to 75. MY GPS doesn't read fractional MPH, but if I set the cruise control at 60 both the speedo and GPS locked on 60 until I changed speed.

Unfortunately I never did a comparison with the stock setup. I just "assumed" the speedo was correct. Nice to know I don't have to pay to have the tire size recalibrated in whatever computer the TB uses for milage.

Alan
 

million-miles

Member
Jan 10, 2012
189
also a lot of speedo's can be off or slow by 2-3 from the factory. When you say somewhat bigger. 2-3 at 70 is hardly any size difference. But im glad you gps and speedo matched up.:thumbsup:
 

asautt

Original poster
Member
Dec 5, 2011
40
jbones said:
You were thinking of 20's like shinnyfeet's, is that what you went with?

Oh yah, don't forget the PICS!



Posted these on another thread I started.
View attachment 18182
View attachment 18183



Got the Forte Koma 20x8 1/2 wheels and Firestone Destination ST 275/45R20 XL. So far-so good. Ride,handleing, and noise level are all good!

Alan
 

Attachments

  • WheelRtFTSmall.jpg
    WheelRtFTSmall.jpg
    55.4 KB · Views: 65
  • TBRTSidesmall.jpg
    TBRTSidesmall.jpg
    56.5 KB · Views: 64

ScarabEpic22

Member
Nov 20, 2011
728
Im not surprised at all, stock TBs come with a 29.5" wheel/tire combo and 275/45R20s are EXACTLY 29.5". For SSs that come with 30.1" tires, they read a tad fast but for regular TBs they will be spot on.

Looks good man, cant wait to see them in person!

(BTW, anyone in the NW want to buy 3 factory SS wheels/tires with ~10k on them? Im trying to sell my remaining 3, the 4th bit a curb pretty badly.)
 

Forum Statistics

Threads
23,273
Posts
637,484
Members
18,472
Latest member
MissCrutcher

Members Online