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Richard S
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Maui Blue has Pirelli P6000 16x225x60 Z-rated.<P>Black Beauty has Pirelli P4000 16x225x60 H-rated.<P>No rubbing problems with either.<P>Jerry

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Guest EDBS0

Tire Rack feels that 225/50-17 will fit.<P>Personally I have had 225/60-16 on an 89.<P>I would like to try 245/50-16. Anyone already tried?

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Have 225x60x16 Michelin X-Ones on my '88. No problems but clearances are tight in the front at full lock, need to be careful about offset.<P>Rears I think could be a couple of sizes larger but is a bit absurd in a FWD car.

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Guest RED891

I'M RUNNING DAYTON WIRES AND GOODYEAR TIRES 22560R16 FILLS UP FENDER WELL cool.gif" border="0<p>[ 04-09-2002: Message edited by: RED891 ]

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Here is a little information you can use as you see fit...<P>The '88-'90 15" rim has 5.5 inches from the back of the rim to the mounting surface. Doing the math, this is 2 inch (50.8 mm)positive offset.<P>The 1991 16" rim is 5.75 from the back to the mounting surface. That is 1.75 in (44.5mm) positive offset.<P>Everything else being equal, you could run a fatter tire on the 15 inch rim before having interference in the inside, as the 1991 rim is 1/4 inch closer to things on the inside than the 15" rim.<P>To calculate a size tire would give you the same speedometer reading as the original 215/65r15. Try this. 65%of 215 = 139.75<BR>Since tire come in 60, 55, 50, 40 etc series.<BR>If you divide 139.75 by each series number, it will give you the metric size that will be the same diameter as the 215's<P>139.75 divided by 60 = 232.9<BR>139.75 " " 55 = 254<BR>139.75 " " 50 = 279.5<BR>That is the ideal size, but you must go up or down to find the closest size that is actually made...<BR>232.9 would be a 235/60r15<BR>254 would be a 255/55r15<BR>Now the next trick is to see if someone actually makes the size.<P>The 235/60 r 15 is a fairly common tire and the diameter would be almost exactly the same as the original tires... next come clearance... the 235 is 20mm (.787 inches)fatter than the original tire, half of that <BR>goes to the inside and the other half goes to the outside. So you need 10mm (.40 in) clearance on each side to go to that size.<P>If someone has tried them it would be interesting to hear the results..

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I was replacing one tire yesterday and was discussing a new set with a guy who seemed to be quite knowledgeable about tires, wheels and brakes. He advised me AGAINST going up to a 225 on my 91, saying that cars with ABS should NEVER do that, it would cause problems with the ABS systems. He said the circumference was different enough to screw things up..that it was a big mistake to make the change. Just thought I'd pass this on...he was familiar with the brake problems on the Reatta and said the change was a factor few considered????? confused.gif" border="0

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The changing tire sizes seems like a bogus argument. Two different tire sizes on the same car may cause some slight problems under ABS braking but the ABS doesn't really care about the actual indicated speed (within limits), but is looking for the differential from one sensor to another. If it is true that a different tire size will affect the ABS, then the worst possible case would be the space saver spare on one wheel.

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Thanks Sahein for posting that Big Ten site I have been looking for the right wheel since Nov 01 and I think Big Ten has it.......now if they does look too cheesy in- person I am sold.<BR>Big Ten changed out my struts, but considered their wheels.<BR>Greg<BR>PS Robert what the name of those struts?????????

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In reply to Barney<BR>I put 235/60/15 tires on the front when I first bought my Reatta. I was pretty happy with the ride and handling, but there was some rubbing when I made a very sharp turn. The tires had a blem defect and I returned them, and when I did I had them put 225/60/15 tires on. I've had not problems with this size.<BR>The rubbing with the 235 wasn't severe so I would have kept them if they weren't being replaced for free.

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Personal opinion but anything over a 215 on 6" rims is liable to give problems with wearing the center of the tire unless you lower the pressure (which has other effects).<P>Was justification I used for going to 7" rims and 225/60 tires. Over that I wold really prefer 8" rims. Personally like a rim the same width (or close to it) as the tread for a street tire.

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I'm wondering if I am reasoning correctly here: The struts mount at an angle, do they not? So a larger rim, say 17", would require somewhat less backspacing than a 15" to avoid contact with the strut. The remaining concern, in the front at least, would be rubbing in the wheel well at full lock or in hard cornering.

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Close but not quite. Is true from a clearance standpoint but you need to take into account the kingpin angle. <P>This is an imaginary line viwed from the front of the car drawn from the top strut nut on the Reatta through the lower ball joint. The continuation of the line should meet the ground at the center of the tire.<P>Too far off the center line and either accelleration or braking will cause torsional forces in the steering which will cause premature wear to the steering and if either side loses traction, the resulting steering reaction would be "interesting". (have often wondered how long those rice burners with the incredible offsets last, cornering must be scary).<P>So if you increase the overall tire diameter, you also must take into account the kingpin angle. I did not worry too much on mine since going from a 215x65x15 to a 225x60x16 increased the tire radius by 9 mm and the Enkei backspacing added 7mm of track to each side. Close enough for government work.<P>Going to a 17" wheel and less offset now...<P>Last car I owned that had a kingpin was a '55 MGA. Any later ones ?

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Very interesting. I did the little drawing you suggested. Just love visual aids. The result seems to be that as one increases the radius/diameter of the tire, the imaginary line from the top of the strut to the pavement moves toward the outside of the tire. Therefore, one must also increase the backspacing or offset to push the tire out to where the imaginary line will intersect the center of the tire at the pavement. Ya?

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I would think that given a choice [which one may not have when transferring wheels], one would opt for wheels with greater offset than the use of spacers. Don't spacers tend to put a lot of pressure on the lugs themselves. The stock [215/65/15] 90 Reatta tire has a pretty big diameter [over 26" I think], and I would like to add 2". This would mean adjusting the offset, which I recall from past posts was between 32 and 40 degrees. Do you have an estimate on what offset would put the center of the tire where it should be?

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GM cars locate the wheel on the center hub and not on the lugs so spacers are not a good idea (at least not big ones - when I put the 3 mm spacers on the rear of the Fiero to clear the struts, I chose that minimal size because there was still enough surface left of the hub to register the wheel. Any larger and I would have gone to other wheels).<P>True, the conical lug nuts used for the stock wheels (part of the reason I chose the Enkei wheels was because they used the stock lug nuts and had a deep enough well for the lock) will provide registration if needed but it is much better to leave that task to the hub.<P>Seems like we are getting into a lot of considerations here that I suspect many people never even knew existed. Dare I say "AR" ?<p>[ 04-18-2002: Message edited by: padgett ]

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Truth. Keep in mind that 1/4" off one way or the other will not make a lot of difference. An inch will be noticable.<P>In some cases this is a good. When I put the Beretta 15x7s an my Fiero, they were in about a 1/2 inch further than the stock wheels & had to put 3 mm spacers on the back for clearance on the wheel weights. Also noticed that the effort to turn the wheel went down (Fieros have manual steering).

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For anyone interested I picked up a tire in the salvage yard for $10. I tried it on my '88 Reatta and it fit with no scrapping.<BR>So what is the big deal you ask? The tire is a P235/60 R 15 SR rated. Most tire books list P215/70 R 15 for '88.

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Guest EDBS0

Don B. in your opinion is there at least 1/4 inch clearance each side to go up to the 245/16/60 size?<P>In past I have used a baseball bat to roll the fender lip. Interference with struts is much harder to adjust for.

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