Euro 280sl cruise rpm question
 

I just picked up an 81 Euro 280sl. The car is cherry, runs great and the price was right. Going thru 26 years of repair invoices I saw that the differential had been swapped out at some point in it's life. Does anyone know what the proper final drive ratio should be on these cars. If not what rpm are you turning at 60 and 75 mph. This thing is turning about 3500 rpm's at 75mph. Is this normal? I'm not used to engines spinning at such high rpm at such slow speed. It is however as smooth as a Swiss watch.

Thanks Matt

Somebody may have swapped in a higher-ratio rear end in order to get more off-line grunt. But in any case, don't worry about it. It will affect your fuel economy, but other than that it will run like a swiss watch, as you say...

Also, I wouldn't expect much less than 3000 rpm at these speeds anyway. You're driving one of the last non-overdrive cars...something that no longer exists.

Both the 107.022 and 107.042 (280SL) have a ratio of 3.58:1. The 107.044 (450SLC) has a ratio of 2.72:1, whereas the 107.044 (450SL) has a ratio of 3.07:1. From what I hear you saying, it sounds like you have the correct rear end for this model.

3500 @75mph sounds normal for a 280SL. High, I know, but it doesn't hurt the DOHC six, as that is its sweet range... :P

280 Sl Rpm
 

Just completed a 200 mile drive of which 1/2 of which was at 70 to 80 mph. I drove my 5 speed stick in fourth gear the whole time and the rpm was between 3500 and 4000. lots of torque and the car ran great.

In fifth the rpm is at about 3000 but less pick up at higher speeds.

steve

'84 280sl 5 speed stick 188k, no. cali