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CntryUSMC
09-09-2003, 03:55 PM
I just bought a 1993 Grand AM SE and my speedometer seems to be running about 10mph fast. For example if it says I am goin 55 I am actualy going 45 or so. Is there anyway can fix this? Thanks in advance.
99GrandAMSE
09-09-2003, 04:21 PM
What size tires are on it?
CntryUSMC
09-09-2003, 05:12 PM
oops ment to add that LOL 195/70/R14
99GrandAMSE
09-09-2003, 07:43 PM
Hmmm ... I don't recall exactly but that isn't the factory size is it? If not, what is the factory size and we can tell you how much this tire size will alter your speedometer :)
CntryUSMC
09-09-2003, 08:04 PM
Originally posted by 99grandamse
Hmmm ... I don't recall exactly but that isn't the factory size is it? If not, what is the factory size and we can tell you how much this tire size will alter your speedometer :)

Well according to several tire shops the standard size is either 195/70/R14 or 185/75/R14.
99GrandAMSE
09-09-2003, 08:11 PM
Hmmm ... well, as you know, if your tires are significantly different in respect to size your speedometer could be off ... if I had to guess, I would have thought the stock tire would have been a 60 or a 65 series but I have nothing to base my thought on :shrug:
blk95ga
09-10-2003, 12:38 AM
Yeah, my 95' has the 195/70/R14.......maybe somebody prior messed with the needles?
LargeFish
09-10-2003, 09:11 AM
I didn't realize any 92-95s came with 14s stock. My stock was 205/60/16.
CntryUSMC
09-10-2003, 04:34 PM
Originally posted by LargeFish
I didn't realize any 92-95s came with 14s stock. My stock was 205/60/16.

would that make a 10 mph diffrence?
99GrandAMSE
09-10-2003, 04:51 PM
Originally posted by LargeFish
I didn't realize any 92-95s came with 14s stock. My stock was 205/60/16.

Your's is a GT though :)
CntryUSMC
09-10-2003, 07:07 PM
Is there anywhere I can go to find out the factory specs for the tires? Haynes didn't say anything about tire size. Or does anyone know how to recalibrate the speedometer?
LargeFish
09-11-2003, 11:24 AM
Right, but I figured SEs of the same vintage would have at least 15" wheels. I'm gonna see what I can find out at edmunds.com

Originally posted by 99grandamse
Your's is a GT though :)

Edit: Yeah I see (at tirerack.com) SE stock was indeed 195/70/14 with 195/65/15 available as an option... Also goofed on the GT size it's 205/55/16, have 17s on the brain lately... the size calculator at http://www.miata.net/garage/tirecalc.html is always helpful. All of the stock sizes including yours should be in calibration. I forget how they drive the Spedo/Odo. but maybe you have a bad sensor or something? Is the odometer inaccruate as well as the speedo? If it's only the speedo it could be an electrical problem.
CntryUSMC
09-11-2003, 04:15 PM
Originally posted by LargeFish
Right, but I figured SEs of the same vintage would have at least 15" wheels. I'm gonna see what I can find out at edmunds.com



Edit: Yeah I see (at tirerack.com) SE stock was indeed 195/70/14 with 195/65/15 available as an option... Also goofed on the GT size it's 205/55/16, have 17s on the brain lately... the size calculator at http://www.miata.net/garage/tirecalc.html is always helpful. All of the stock sizes including yours should be in calibration. I forget how they drive the Spedo/Odo. but maybe you have a bad sensor or something? Is the odometer inaccruate as well as the speedo? If it's only the speedo it could be an electrical problem.

To be honest I am not sure. I always thought the odo was run off the speedo.
mikem220153
09-11-2003, 10:34 PM
Look on the back of your drivers side door for a sticker with your recommended tire pressures. That usually gives you the factory tire sizes.