with a 315/35 the 35 means the side wall is 35% of the size of the 315 width

 

Yea I understand that, but the outside diameter measures the same as a 245/45. I still just don't understand how that would throw your speedo off by 6% with a tire that is wider, but not taller/shorter in any way.

 

i'll be sure to tell the police that next time i get pulled over for speeding

i still think that is not feesable....

where's the hardcore admins when you need'um?

 

my 275/35/18s measure the same as my old 275/40/17s so there is not a big difference unless you get one with a bigger side wall

 

not all 245/40's are going to have the same sidewall height as all of the 315's.

Some manufacturers just cut their tires wider.

FOR INSTANCE, BFgoodrich R1 tires for 315/35/17's are 25.5" tall, and are 816Rev's per mile

the same exact tire's, in 245/40/17's are 24.2" tall and have 860 revolutions per mile.

Make more sense?

BTW, here's the spec sheet that I took this info from

 

Oh, BTW, you can do that for every single tire listed, Goodyear Eagle F1's are 25.7" tall for 315's, but only 24.7" tall for 8" wheels

 

cobra gauges FTW...

 

yea ifffffffffff you can sping your block to 7k.. lol I waited n waited for an auto mach 1 cluster so i wouldnt have that issue.

 

considering he has a 2003 cobra, I would imagine that he can spin it that high


plus, it doesn't make much sense to have those if your not running a boosted car, the boost gauge will just sit there at 0psi forever

 

i have a solution for the boost gauge....turbonator!!!!!!!!