Lately, my 1985 300d has been... err... a tad sluggish. Moreso than usual, its normal 0-60 time of 14 seconds has been increased to well above 20 seconds.<br> <br> Here are possible factors, but they don't really answer my question. Any suggestions would be VERY much appreciated, for I'm fearing a bigger problem than just one of the following.<br> <br> >I have 205/70/14 snow tires on the back, which will come off soon. These, I'm told, COULD give the car a slower 0-60 time.<br> >It is also winter, but the car even drags a bit during 50-degree days.<br> >There is NO power at ALL above 3,000rpm. It seems that just after the turbo kicks in, the car slows down. This evening, I floored it from a dead stop on a level road. The car pulled alright through 1st, okay through 2nd, but when it got above 3,000rpm in third gear it just stopped pulling. With the pedal FLOORED, the car barely had the power to get up to 4500rpm and shift to 4th. When I got the car last August, its power zone was past 3500rpm, and now barely WILL go past that.<br> <br> I hope to hear that it's just the cold, or the tires, but I fear a bigger problem.