I was getting excited about your manual 240D until you said that a normally aspirated 300D could outrun it. That should not happen. Your 240D is not running right.

As far as reliability and going to Alaska. I drove two 240D's a total of 808,000 miles. The first one went 285,000 miles and the second one 523,000 miles. During almost all of those miles in the second one, I was doing business travel that required me to ABSOLUTELY be on time wherever I went.

It was routine for me to get up in the wee hours and drive 300 miles to be at an important meeting. My company and my own livelihood depended on it. Neither of these 240D's EVER caused me to be late or miss a meeting due to mechanical failure. The closest I ever came was losing an alternator belt about 8 miles from Hope, Arkansas. I rolled into hope, found an auto supply, called ahead to let them know that I might be late, got a belt, stripped to the waist, put on the belt while listening to the car phone, took a call, kept working, went in and scrubbed and dressed and was on time, BARELY.

The scariest part was spending that much time in Hope, Arkansas (Bill Clintons birthplace.)

These cars MUST be among the most reliable cars ever put on the highway.

Enjoy your trip,