my street radials died. im stuck with the stock 245 tires. do i have to retune to get my speedometer to read properly? cause this thing is pretty off. i thought i was doing 45 but then i relized EVERYONE was passing me....im sure the whole world isnt full of speeders.

 

what size tires died? If your off that much then yes unless you have a speedcal connected then just change the switched to comp. for the tire size.

 

depends on how high the tire wall was , if was significantly smaller or larger then yes , speedo adjust.

 

i hope i have a speedcal! where would it be located?

 

my tires were like 295s lol.

 

i'm not talking about width. it would be rim heighth. like 17's or 18's . a speed cal is something you add to your car. if you bought it used and you think you possibly would have one its under your shift boot.

 

it was 16's. tires blew on my and had to go to a little shop to get used 245's. under the shift boot? damn i dont think i have one. then again i have torn up my car enought to see.

 

Tires really wont change your speedo if they the correct aspect ratio and such.

 

well its a little black box about 2"x4" you can't miss it , you probably don't have one . the most common application is on a gear swap. try to find a police radar station to see how much its off by.

 

What was the entire tire size before, and what is it now?

Aka, was it a 295/40/R17? the middle number tells you how tall the sidewall is in comaparasion to the width of the tire (first number). If the ratio is the same, no retune is needed.

Unless you drastically changed DIAMETER nothing will change on teh speedo. A little change in diameter you won't even notice (1-2 MPH).