Directional Rims On Ls400

[1991/LS400]

I am just about to change the tires on my 91LS 400,I noticed in the owner's manual that is impotant to keep the rims on the side that is marked on them.

My car was driven by previous owner with 3 right side rims and 1 left... the other

left one was used as a spare wheel(in bad shape),my question is:how important is

really to keep the correct side on the rims?

[1990LS400]

My understanding is that having the wheels on the correct side was important for cooling the brake rotors but I doubt if it is an issue in everday driving. I noticed that the buyer of my 90 LS has the wheels on the wrong side (he didn't notice that they are directional) and I mentioned it to him a couple of days ago. The brakes on the early LS are pretty poor compared to ones starting in 93 (?) when the rotor size was increased and the tire width was increased from 205 to 225. I was a little shocked after I bought my LS in 1990 when Road & Track listed it in its "Road Test Summary" section as having just about the longest stopping distance of any car and far worse that all its competitors. Although ride harshness is increased quite a bit, changing from 205/65-15 to 225/60-15 tires dramatically improves braking and there is almost no impact on speedometer accuracy. If you try this switch, stick to the bottom range of inflation (30 psi) to keep the ride harshness down.

[VBdenny]

Do the 225/60's fit right on the standard rims?

[92Lex]

I have 3 right rims and 1 left on mines....everythings going smooth. 225 should fit on the stock rims without any real problems, the sidewalls are just wider..better handling plus it helps protect your rims from curb marks too.

[1990LS400]

I agree with 92Lex. One of the benefits of the 225/60-15 on the OEM Lexus rims is that it makes it a harder to "curb" the rims. 225/60 is well when the allowable width for 6 1/2 inch wide rims according to my Dunlop guide. When Lexus started putting 225/60-16 tires on the LS in 93, it chose 7" wide rims - only 1/2 inch wider than previous.

[silvermate]

The directional wheels were stock on the first gen LS only..... and they were 15's, 225 60 will only fit the 16 inch rim, that was stock from the gen 2 and later..........

the correct tire for the 15 inch wheel would be 205 65 15

[SRK]

the correct tire for the 15 inch wheel would be 205 65 15

Exactly right. And Lexus themselves advises only two optional tire sizes for the 15 inch wheels, 215/60-15 and 215/65-15. I have the 215/65-15 on my car now, and find they look and work well.

[1990LS400]

SRK and Silvermate,

Sorry to disagree but 225/60-15 tires fit fine on the 6 1/2 inch wide 90-92 LS directional wheels and they ensure that speedometer accuracy will be almost perfectly maintained. 215/60-15 tires, however, introduce a fair amount of inaccuracy - get out your conversion tables and you can verify what I am saying. I used 225/60-15 tires on my 90 LS for several years after the original Eagle GA's wore out and they fit and looked fine.

More important, they provided vastly improved braking. 205/65-15's provide too small a contact patch with the road to provide really good braking on a 4,000 pound car. The 205/65-15's that came standard on our Camry, however, do provide acceptable breaking - but our Camry weighs about 1,000 pounds less than the LS.

[silvermate]

205/65-15's provide too small a contact patch with the road to provide really good braking on a 4,000 pound car

205/65/15 is the tire that the first generation LS400's with the OE 15 inch wheels came from the factory with

[1990LS400]

Yes, 90-92 LS400's sold in many countries including the U.S. came with 205/65-15 tires mounted on 6.5 inch wide, 15 inch diameter wheels. I bought an LS400 in early 1990 and my next door neighbor bought one in the fall of 1989. We both kept our 90 LS's for over 13 years and we both experimented with different tires and wheels. My point is that the horribly long stopping distances of the early LS was caused mainly by the tires being so small. True the brakes are a bit too small too, but the main cause is the small tire size.

There are lots of on-line tire size calculators but an especially good one is at http://www.1010tires.com/TireSizeCalculator.asp

Put the original tire size 205/65-15 on the left side of the calculator and then, one at a time, put the other three sizes we are discussing on the right side of calculator: 225/60-15, 215/60-15 and 215/65-15.

You will see that the 225/60-15 size provides by far the most speedometer accurancy - only 1/2 of 1% difference from the OEM size. And 225/60-15 also provides the largest section width increase (over 3/4 inch) and thus the biggest improvement in braking.

Changing to 225/60-15 tires on the early LS is an inexpensive way to improve safety since there is no need to change wheels. Probably one reason this size is so widely available is that 5 and 7-series BMW's came with this size for quite a few years.

[92Lex]

205/65-15's provide too small a contact patch with the road to provide really good braking on a 4,000 pound car

205/65/15 is the tire that the first generation LS400's with the OE 15 inch wheels came from the factory with

205-65-15 is the correct size Lexus equipped their 1st gen LS400's with but he wants to upgrade to a better tire. Not everything coming from a manufacturer is going to be perfect.