Hi guys just bought an 85 300D with unknown miles, clocked apparently stopped at 186k in 1998 sometime. When I started to drive the car I couldn't get it over 40 mph. I changed the fuel filters and it seemed to be fine right after I changed them. The day after I changed it it got very sluggish in the morning. The fuel guage my be off, as it seemed to run better after I put five more gallons in the tank that already read 1/3 of a tank, bringing it to 1/2. Any ideas as to what I can do to keep the car from running sluggish, besides changing the fuel filters?