[browntown]

Hey folks, have a question. I have a 1990 lx with a stock tire of 175-70-14. I bought some gt 15" rims since apparently the chasis is the same, and the car doesnt know which one it is using. But here's the interesting part. Stock tire size for the 1st gen gt rim is 195/60/15. But if you crunch the numbers on a site like http://www.miata.net/garage/tirecalc.html you'll see that the speedo will be off more with 60 series than say 55 series tires. so here's my question, were the gt's speedo calibrated differently, or is the .3 inches in difference so negligable that ford said screw it. Im looking to buy tires tomorrow, but not sure if I should get the 55's since they are within .1 inches of the 14 inch tire diameter, or go for the 60 series since thats stock for the gt rims.

any help appreciated

****edit something interesting i have discovered looking at tire sites is that 195-60-15's are much more available and are cheaper than the 55 series. this is kind of pointing me down the 60 series tire even though it will make my speedo off by 2.4% (when speedo reads 60, i'll really be going 61.4mph)
browntown 90lx

 

[Pimp_scort_89_GT]

Well the GT and LX spedos were different. the GT being round and the LX being square. I'm sure Ford would have said screw it though if the calibration was the same. that much diff won't really be that obvious. and the 15's from the GT will bolt right up. Little known fact: 79-93 Mustang rims will bolt up to 1g Scorts as well. So if you are ever in the mood for some 16 look toward a 92-93 Stang GT Anway, I would go for the 55's if you are that concerned about speedo accuracy, not to mention they aremore stable in the corners, but if you don't care, and you want a smidge more ground clearance and a little less fender gap go with the 60's. I believe I have 195 65 15,s on my car, but I did want a little higher stance for when I go offroad, which is more offten than one would think since I live in the AZ desert. Also some concerns with the wider tires.... When loaded down in the rear mine rub the back of the side skirts when I hit bumps, since you have an LX this might not occur, but I would recomend rolling the fenders just in case. This is accomplised by using the biggest hammer you can find and whackin the hell out of the flat lip that comes off of the bottom of the inner fender (You'll know when you see it) Just take off your tire and whak it in an upward and outward fasion until it has a nice radius to it.

 

[browntown]

hey thanks pimp scort, i think just for the price differential ill go for the 60's (unless someone has a good argument why i shouldnt). Its only a difference of about 2mph @ 80mph, and about .2 inches btween the two series radius. depends on what the tire guys have on sale. if its 50-100 dollars cheaper for the 60's, well that makes up my mind in a hurry. regarding the mustang wheels, you are correct that the bolt pattern is correct, but the offset is different, and does effect the "track" of the car. How much so I dont know as I've never been in a scort with rwd rims on it. As for the fender lip, a product of living in a part of the world that salts the roads for 6 months a year due to snow/ice, my rear fenders are pretty well rusted away. but im skilled with the whack a hammer technique if it turns out i need it.

Oh and my LX has the same cluster as the gt's round guages with tach, i think they called it the sport guage setup.

thanks again, appreciate it man.

browntown 90lx

 

[PTMD]

Watch for that fender scrub if you use rims from a Mustang too.The offset is different so you get the same thing as if you put on wider tires.

 

[Pimp_scort_89_GT]

I put a set of 205 55 16's from my Mustang on my scort for a couple days. It looked awsome, and the ride was great until I hit a big dip and whiped out the sidewalls of the rear tires.

 

[browntown]

just an update, mounted the new gt rims and rubber today, and it drives so much better than the skinny 14" tires that were stock. the 55 or 60 series was settled quickly as most tire shops dont even stock 195/55/15's and they are really expensive. the 60's are working aokay by me though. couple cautionary notes. I bought these gt rims off ebay from a fella who said he found them in the corner of his warehouse and they were NOS gt rims, never mounted. Well the expert eye of my tire guy said they were most likely remanufactured. There was a little bubling under the clear coat, and when spin-balancing one of the rims had a little run-out. I always kind of figured that was a possibility when i bought em, but I got a good deal so I'm not complaing. Caveat Emptor. Another cautionary note is lugnuts. When you buy rims make sure you get the proper lugnut with them. I didnt know this and when I took the gt rims to the tire shop, he said where are the lugnuts? I asked, isnt that a standard thing you keep around? He said everyday someone brings a set of rims in they bought from 'some guy' without the matching lugnuts and you gotta find the rim manufacturer and get the correct ones. Luckily since my gt rims are ford wheels, I went to the local ford dealership and was able to buy some. They list for $3.70 a piece!! I was able to talk the guy at the parts desk down to $2.13 a piece but were still talking close to 40$ for the set. Lesson learned.\

browntown 90lx

 

[Rob]

Hello:

I put a set of 205 55 16's from my Mustang on my scort for a couple days. It looked awsome, and the ride was great until I hit a big dip and whiped out the sidewalls of the rear tires.

Could you explain exactly what happened?

To my best knowledge by compressing springs you do not change
a distance from suspension elements to tire?
So why a dip could be a problem?

Thank you,

Rob.

 

[bpletch1]

Rob,

You don't change the distance from suspension elements to tire, but you DO change distance from BODY elements to tire. My guess would be that the additional offset plus the wider tire added to the suspension flex cause the tires to contact the fender lip and cut the sdiewalls of the tires.

back me up, Pimpscort???

 

[Diane]

Sounds good to me. If you have a good feel for the way your car should handle, using the stang wheels is not the way to go. It seriously affects the handling. In normal street driving you won't notice it.

I don't believe in putting RWD offsets on FWD cars in most cases, the offset difference it just too extreme.

My .02