Compression values PSI

[Benz280]

The topic of compression is all over the board re 230 vs. 250 vs 280.
For the record, what is considered prefect and then acceptable ? 

[Benz Dr.]

Somewhere in the 170 - 180 PSI for 280 and 250 is optimal. 230 can be as low as 150 PSI with stepped pistons or about 165 PSI with flat top type. MB will tell you a 10 - 15% loss is already rebuild time but a 280 will still run OK at 140 PSI. When you get down to 120 PSI you will have problems with hard starting and probably oil smoke.

[Cole]

Hi,

The compression test on my 250SL yesterday was:
Cylinder 1 - 170
Cylinder 2 - 170
Cylinder 3 - 165
Cylinder 4 - 170
Cylinder 5 - 170
Cylinder 6 - 175

On the the 280SLs and 250SLs, what was the compression when they left the factory?

Thanks!
Cole