987 Boxster 18" Wheel Questions

[eslai]

I believe you will find a sticker on the car when you open your door that tells you what the pressures should be for the entire range of offerings from Porsche.

By the way, I still have a set of 18" 987 wheels if anyone is interested.

[Savanh]

Will those fit 99 boxster? Thanks!

[vincesf]

[QUOTE=eslai]I believe you will find a sticker on the car when you open your door that tells you what the pressures should be for the entire range of offerings from Porsche.

On my 2008 987S, the sticker only refers to 19" wheels, as that was the original equipment on my car. I contacted the dealership to purchase a replacement door sticker, reflecting 18" wheels, and was quoted $235.00 for the sticker! Apparently, the sticker needs to be very specific as to the serial number of the car, etc. I think I shall pass on that one, and I appreciate the information from Husker Boxster, providing me with the correct tire pressure for 18" 987S wheels/tires, at 26 lbs front, 33 lbs rear.

Vince

[roadracer311]

I run my 18's at about 29/36 lbs. They seem to wear more evenly. At the recommended (lower) pressure, they were getting the classic under-inflation wear pattern (it was subtle, but enough that it shortened the useful life of the tires by about 10%)

On long trips (I've done a couple 1,000 mile round trips to Oregon) I've run them as high as 32/38. I got 29.8 mpg on the way up, and 28.8 mpg on the way back with the AC on :-)

Your car looks great! (I'm pretty sure I've seen it around the Richmond district)

[eslai]

Originally Posted by vincesf

On my 2008 987S, the sticker only refers to 19" wheels, as that was the original equipment on my car. I contacted the dealership to purchase a replacement door sticker, reflecting 18" wheels, and was quoted $235.00 for the sticker! Apparently, the sticker needs to be very specific as to the serial number of the car, etc.

WOW seriously!? I can't believe they would have a different sticker! Mine shows the pressures for 18" and 19", although mine came with 18's. That's just ridiculous! And the price for a replacement is damned nutty!

Savanh: They will fit, and here's my for-sale thread if you want more info.

[husker boxster]

The sticker in my door also only refers to 19" wheels.

I wondered if the TPMS would send a warning if it thought you'd overinflated the tires but a quick check of the owners manual says it wouldn't. It only sends a signal if your tire is low (3-6 psi below recommended) or if it detects a tire is flat. So adding extra air wouldn't bother it.

BTW...
Why don't you want to keep the 19s on? They look great on your car.

[vincesf]

BTW...
Why don't you want to keep the 19s on? They look great on your car.[/QUOTE]

No real reason, other than the 18" wheels look good as well and ride a little smoother on San Francisco pot-holed streets. I will probably rotate them back onto the car after the tires wear out on the 18" wheels.

Vince

[vincesf]

Well, the conversion of wheels was very easy, and the Tire Pressure Monitoring System was very easy to reprogram to 18" wheels, as outlined in the manual. Again, I appreciate the recommendations for tire pressure. On my car, a cold temperature of 26 psi front and 33 psi rear seems to inflate to 29 front and 36 rear when warmed up. Keeping in mind, my car is equipped with PASM and factory 5mm spacers, my impression is that the ride with 18" wheels/tires is virtually the same as with 19" wheels/tires, on smooth stretches of road, and as expected the 18" wheels/tires are smoother when the road conditions get rougher. All in all, if you must have the look of the 19" wheels and your road conditions are good, the penalty in ride compliance is not all that significant. As for handling, the 18" wheels seem to make the car lighter on its feet, and a bit more tossable on the backroads, which I like. As for looks, I like the 19" wheels/tires better, and will keep them in storage for future use.
Vince

[husker boxster]

Did you swap the monitors or purchase another set? If you swapped, was it easy?