Spoolin'Jim
Well-known member
Hello everyone.
Back in November, my mileage went form a rock steady 52.x mpg to 44.x mpg and then worked its way down to 41.x mpg. I have kept records of every tank since buying the car new in August of 2006. It is a 06 Jetta TDI. Looking back, the lowest tank I had ever had prior was the very first tank, which was 48.2mpg. Ever since then it had jumped up 50-53mpg. Even when it was -20deg F, I was still averaging 48-49mpg. Now I’m struggling to get up to 42mpg. I had the dealer look at it and saw nothing wrong. Air filter is fairly new, brakes aren't dragging from what I can tell with it jacked up (though pads are worn at a strange angle but that’s a different question), tires are pumped up to 42psi (44 is max on sidewall), and I have tried several different brands of diesel and additives with no improvement. I tried unplugging the MAF and driving it and noticed no difference really in performance, and no difference at all at mileage. I’ve tried plugging the car in overnight so its warm from the start, and it still gets about the same as from 0deg F starts. The car is due for its 60k in 4k miles. I will have them change the fuel filter and air regardless unless I find out what the real problem is befor then. My driving habits have not changed in a way to degrade my mileage (if anything, I’m trying more desperately to get past 42 than before). The only thing that has changed has been the tires. I went from the stock Bridgestone's to Michelin Triple Treads back in early November, but the mileage decrease wasn't till the tank after they were put on. A 20% decrease seems a lot for a set of tires to do anyways. Does anyone have any insights as to where to look next? If it keeps its downward slide, I might trade it in. Yesterday it decided a bulb was bad, too, so I have that light on the dash despite not finding any burnt out bulbs. Also, the past few days, it seems like it has no power till about 1400rpm, where it then feels like someone flips a switch and it gets much peppier. It also takes 2-4 tries to start it in the morning (not plugged in and –15F). It wasn’t like that the past 2 winters at all. Even at –25F it cranked right up after 2 cycles of the glow plugs.
Okay, I think I’m done rambling! Thanks in advance!
Back in November, my mileage went form a rock steady 52.x mpg to 44.x mpg and then worked its way down to 41.x mpg. I have kept records of every tank since buying the car new in August of 2006. It is a 06 Jetta TDI. Looking back, the lowest tank I had ever had prior was the very first tank, which was 48.2mpg. Ever since then it had jumped up 50-53mpg. Even when it was -20deg F, I was still averaging 48-49mpg. Now I’m struggling to get up to 42mpg. I had the dealer look at it and saw nothing wrong. Air filter is fairly new, brakes aren't dragging from what I can tell with it jacked up (though pads are worn at a strange angle but that’s a different question), tires are pumped up to 42psi (44 is max on sidewall), and I have tried several different brands of diesel and additives with no improvement. I tried unplugging the MAF and driving it and noticed no difference really in performance, and no difference at all at mileage. I’ve tried plugging the car in overnight so its warm from the start, and it still gets about the same as from 0deg F starts. The car is due for its 60k in 4k miles. I will have them change the fuel filter and air regardless unless I find out what the real problem is befor then. My driving habits have not changed in a way to degrade my mileage (if anything, I’m trying more desperately to get past 42 than before). The only thing that has changed has been the tires. I went from the stock Bridgestone's to Michelin Triple Treads back in early November, but the mileage decrease wasn't till the tank after they were put on. A 20% decrease seems a lot for a set of tires to do anyways. Does anyone have any insights as to where to look next? If it keeps its downward slide, I might trade it in. Yesterday it decided a bulb was bad, too, so I have that light on the dash despite not finding any burnt out bulbs. Also, the past few days, it seems like it has no power till about 1400rpm, where it then feels like someone flips a switch and it gets much peppier. It also takes 2-4 tries to start it in the morning (not plugged in and –15F). It wasn’t like that the past 2 winters at all. Even at –25F it cranked right up after 2 cycles of the glow plugs.
Okay, I think I’m done rambling! Thanks in advance!