I just bought a new 94 celica gt about 3 weeks ago. They have stock rims but very odd sized tires. instead of the 205/55-15, they have 225/50-15. I don't know if this is due to that but my speedo is off by about 4mph going 40mph, radars show me at 36mph.

Please let me know if i should go with stock 205/55 or if the 225/50 adds anything valuable to the ride. I really have no clue. Only thing i can think of is handling.

I believe stock is 205/55 or 205/50 or something like that. 225/50 is far too big and is the cause of the inaccurate speedo.

well. they fit and run smoothly as far as i know. But i don't know the adv. and disadvantages to the wider 225, thiner 50 compared to the 205/55 stock.

-Borrazca+Oct 31, 2004 - 6:57 AM

ummm 50 series is smaller than 55. not by much but a little.. it could possibly attribute to your speedo saying your goin faster than you really are.. less of a rotating mass, will trick the speed sensors

If you dont plan on getting aftermarket rims then check your owners manual for the stock tire size.. it looks from your 1st post that you have done this.. that is the correct size for your vehicle in stock trim... general rule of thumb:

15" wheel - 60 -65 series
16" wheel - 50-55 series
17" wheel - 45 series ( sometimes 50 but with a lowered car this usally wont fit)
18" wheel - 40 series

keep in mind that the smaller the side wall the ruffer the ride will be.. speed rating also affects this (the higher the speed rating the stiffer the tire will be). along with other suspension components

For example:

I am currently running Tein lowering springs (stiff version) stock struts (stiffer than I would like) 17's with 40 series tires with a speed rating of "Z"

this all translates to: WAY TO STIFF...LOL it actually really sucks.. the sidewalls are EXTREMELY stiff... which would be alright if I had softer springs/struts.. but because of how stiff everything is I feel every crack in the road.. which I like to some degree but its kind of annoying... and to give you an idea of just how bad this is.. My from calapars keep working them selves loose on the lower bracket that mounts it to the spindle.. I have locktightened them down 3 times now and it still works itself loose... some of this might be due to the rotors/steel brake lines/ pads that I have over heating the bolts (the whole calapars prolly need to just be replaced) but alot of it I think is due to the stiffness of the suspension.

Like I said before if your just gonna stay with stock wheels etc then buy tires that are the same size as in your owners manual(not sure if differnet models came with different tires etc) also I wouldnt go above a "H" speed rating.. that's approx 120 MPH which you more than likly wont get over very often, belive cutoff is 126mph

Hope that helps and didnt confuse you more >>

The 94 Gt came with 205/55/15 tires on it, but somebody changed it over to 50 series tires probably for the same reason I am thinking about doing it.

Availability and Price!

I can get the 225/50/15 cheaper and most places carry them in stock, unlike our stock size.

This post has been edited by gas65: Nov 5, 2004 - 4:43 AM

Here's a useful website for you Tire size calculator
You can enter different tire sizes and it will show the difference in diameter etc. It even calculates speedo error.

Incidently, 205/55-15 and 225/50-15 work out as exactly the same diameter.

225/50r15 was a much harder tire to find in stock. Every place i checked had to order them. Our stock 205/55r15 was in stock everywhere. Also, the prices are exactly the same.

I just got Yoko Avid V4S 205/55...... heh... umm.... maybe i just gotta break them in so they get better.. dunno. My OHTSU (falken) 225/50 were bald but still handled better, but didn't accelerate as fast due to weight.

I just gotta get used to the reduced handling, enjoy my accel, and live with tires that i don't gotta fill up every 3 hours. >>

I am running 215/35 - 18 and my speedo seems to be pretty close probly like 1 mph off at 70.