peterls

So, finally I found my favorite wheels from a 1999 LS400 for my 1990 LS.
However, I just realized that wheel circumference on 225 60 R16 is much bigger than on 205 55 R15... so that will result in about 10% difference in speed.

However, 1993 and 1994 were also 1st gen, and they used 16" wheels, same tire size as 1999 LS. Should I adjust anything for the new tires? Just get my old speedo recalibrated? Or get a speedo from 1994 LS? I guess the wrong speed reading may influence how the engine works?

dc893

The car will be fine. You just have to remember the speed difference while driving. I did the exact same thing for my 92 with 98 wheels. If you go down to a 225 55 r16 the speedometer should be very close.

PureDrifter

iTrader: (10)

considering that the 89-92 LS400 stock tire size is 205/65-15 the difference to the later tire size is within the limits. not 10% as you stated.

dc893

http://www.tirerack.com/tires/Option...0&autoModClar=

peterls

thanks pure drifter! You made me check my math again and I found this site:

http://tire-size-conversion.com/tire-size-calculator/

and you're right, the difference is only 4% (don't know how I calculated 10% initially).

cgawelko

Isnt it calculated for 16" rims anyway?? Mine came with 16s so im hoping it was calibrated properly before leaving the dealer...

knut1

Don't worry about the rim size, it's the tire size that matters. You can get both too small and too big wheels depending on the tire dimensions.

I have 225/55-16 on my '92, the stock size is 205/65-15, that is about 1% difference and neglictable.

cgawelko

I have 225/60/16. I think mine might be off a little...

knut1

It's only about 4%, and you should be fine. Try the tire size comparison calculator on the middle of this page to see the difference in odometer reading etc :-)

http://tire-size-conversion.com/tire-size-calculator/

cgawelko

I tried that, doesnt say any numbers for 100+mph lol I go 95 on the way to work every day (according to my speedo...) so im worried im going over 100 when I do it

knut1

Yes, you are right, maybe it suddenly drops out of the 4% difference when you pass 100, so that you drive in 150mph when the speedo reads 100

cgawelko

Well when im cruising at 95 which is 10 over the limit, its acceptable. but I want to know if my speedo reads 95 what am I really doing? its one thing to speed on purpose but no cop believes the tires size story

PureDrifter

iTrader: (10)

you're doing '95.

225/60-16 is the stock size for '93+ cars.

Regardless if you get caught doing 10 over you're not going to get off on tire size. If you even bring it up they'll ask you why you knew it after you got the ticket and not before when you were speeding.

cgawelko

dang these cars change everything from year to year dont they? but that helps. Less worry about that then. too many cameras out here to risk it