Trail Boss 18’s on Stock RST?

[CamGTP]

Thanks bro.

 

If thinking with logic and a mechanics type mindset because I am one, then sure that makes me a douche.

[Gangly]

11 hours ago, Mike Borowski said:

You give GM Truck owners a douche reputation, good job. 

Don't get mad when somebody questions your efforts, especially when putting forth any mental effort at all would have yielded the results you needed.

 

Talk about creating a reputation for yourself....

Edited February 3, 2022 by Gangly

[vfm2010]

 The 18" Trail Boss wheels fit on a RST at stock height with no issues. Speedo runs about 2mph fast.

[Mike Borowski]

1 minute ago, vfm2010 said:

 The 18" Trail Boss wheels fit on a RST at stock height with no issues. Speedo runs about 2mph fast.

Thank you for the straight answer

[newdude]

On 2/2/2022 at 3:38 PM, Mike Borowski said:

would 275/70/18 mess up my Speedo?

 

 

If your RST came with 20s, no.  If it came with 18s, yes.  

[Gangly]

9 hours ago, newdude said:

 

 

If your RST came with 20s, no.  If it came with 18s, yes.  

The 20's have a 33" overall diameter tire and the TB's have an approximate 32" tire.  If you go from 20" wheels and tires to 18" TB or AT4 wheels and tires your speedo will be off since the new set is slightly smaller. 

 

I went from factory 20" wheels and tires to the 18" AT4 wheels and tires and my speedo is off by about 2 mph at 70 mph.

[newdude]

9 hours ago, Gangly said:

The 20's have a 33" overall diameter tire and the TB's have an approximate 32" tire.  If you go from 20" wheels and tires to 18" TB or AT4 wheels and tires your speedo will be off since the new set is slightly smaller. 

 

I went from factory 20" wheels and tires to the 18" AT4 wheels and tires and my speedo is off by about 2 mph at 70 mph.

 

 

Stock RST size is 265/65R18 which is 31.5".  

 

OP wants 275/70R18 on Trail Boss wheels so 33" tires.  If his RST came with 265/65R18 it will be off 3mph at 60mph, so with 275/70R18, the speedo will read 60mph yet actual vehicle speed would be 63mph.  If his RST came with 275/60R20, his speedo won't be off.