Bad mileage

I have an 03 jetta tdi and been having bad mileage it has 63000 miles on it. at 53000 i replaced the fuel filter and the air filter i change the oil every 5000 miles with castrol syntec 540 it seems to run fine i do notice it seems to smoke at night. any suggestions oh i almost forgot Ive been easy on her too and that tank only got me 500 miles

There are so many threads on this your best friend is going to be the search function. Here are some keywords that might help. Also, when searching, try using the advanced search "seach thread titles only" I'm also going to assume since you're under the TB interval, it has not been changed and timing is on. And of course, the first thing to consider with any mileage question is driving conditions and style. Transmission has a big impact too.


Snow Screen
Air Filter
Intake Cleaning
Alignment
Tire Pressure
Fuel Temp Sensor
Coolant Temp Sensor

The list goes on and on.

I don't think castrol Syntec is the right oil... is it an automatic transmission model? 500 seems about right... are you vented?

Castrol Syntec 5w40 meets 505.00 and is designed for his VE engine.

for whatever reason... I thought it was an 04... my bad...

its a 5 speed and i did vent this tank and i thought the t belt got changed at 80k not 60 maybe il take it to oilhammer.

To accurately gauge your MPG, you'll want to vent every tank skipping around will throw your numbers off.