205/55 vs 225/50 Options

[Borrazca]

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.

[NEVERSTOP]

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