Just got back from our trip. These cars are the only way to travel Put on about 1800 miles, alot of it pulling mountain passes with the A/C on. Never had to drop down a gear. The 'ol girl just blasted on up the road. Even with the outside temp in the 90's, the engine temp never went over 100C. I was usually running between 70 to 80MPH.
But I am a bit surprised at my gas mileage. I calculated it last night over the whole trip, and it came out to 22.4 MPG. Quite a bit lower then the 25 MPG I calculated awhile ago with my local commuting. But then with the higher speeds, altitude, and with the A/C on, that may be about right.
Only mishap was discovering a loose A/C belt. I thought I had a bearing going out with the intermittant squeeling going on under the hood. Then I lifted the hood with the A/C running and saw the belt flopping around like crazy! Jeeze! (What a PIA to tighten! Who figured out that set-up?!)
And it used no noticable oil either. Dip stick level looks the same as it was before we left last week.
But I need to find a tire shop that can balance these tires properly. Took it in to where I bought them(Les Schwab) for a re-balance before we left, and they still shake at speeds over 70mph.

__________________
past MB rides:
'68 220D
'68 220D(another one)
'67 230
'84 SD
Current rides:
'06 Lexus RX330
'93 Ford F-250
'96 Corvette
'99 Polaris 700 RMK sled
2011 Polaris Assault
'86 Yamaha TT350(good 'ol thumper)

I am glad to hear that your car did good one the trip .

So where did you go exactly on your trip?