Thanks Compress Ignite. That was very helpful and I am saving in My Favorites. I had my tires rotated and balanced today. It was 10,800 miles ago when I had them done at Firestone. They have 35K on them now (and I meant they were new, and now have 40K on them but could see how that read differently...my apologies) and Firestone said they looked like they only had about 15K on them and are in great shape. They had also inflated them to 36 psi and I had them put back down to 27 psi. I asked why they did this and said that is what they had in their system for my car...is that possible? My tires are rated at max 45psi (not low profile but standard). I will definately pay close attention to this area from now on and always check my tires correctly! Anyway, thanks to all for the helpful info.

I used to Inflate the First set of Michelin Xs I Owned to the Max PSI figure
ON THE TIRE SIDEWALL. 35 PSI
Foolishly, believing I'd get the best Fuel Mileage And Most Longevity of Tread.
Well,I did.
That SD regularly enjoyed 27MPG in mixed driving,with not a few JackRabbit starts.
The Michelin Xs (80,000 mile treadwear warranty from Michelin) still had usable
tread at 120,000 miles.

BUT,If I'd gotten "In a Tight Place" in an emergency the Tires might have shown
all that High Pressure Running to me in a way I'd have regretted.

__________________
'84 300SD sold
124.128

Are in the Business of SELLING tires.
[AND relieving your Pocketbook/Wallet of the burden of excess cash.]

They are NOT in the business of inflating your Mercedes tires to the Proper PSI.

(Can you buy Michelins at Firestone?)

Please note My Caveat about Tires:

Michelin makes ROUND tires.
A bunch of other people Manufacture TugBoat Gunwale Protection Devices.
That I WILL NOT BE CAUGHT DEAD ROLLING AROUND ON.

__________________
'84 300SD sold
124.128

I'll look into those Michelins next time! I have some Dunlops right now but would never expect 80-100k in any tires I have ever bought. Wow!