Engineers<3Diesel
Veteran Member
Wow this one got out of hand real quick!
I don't think there is a clearly defined point which you could say all motors are broken in and you should get the best mileage. It is heavily dependant on how they are driven. I suggested in post 15 to report back at 20k miles (heck at 10K you may see significant improvements). That seems like a lot, but in my 2006 Cummins, I didn't see my best fuel mileage until around 60K miles so diesels do take a long time to break in.
Also as a few other folks have mentioned, you will not get the EPA rating in the winter due to a few factors. Winterized fuel has less energy and colder temperatures creating more drag are the main culprits. Just one of the realizations of winter that we have to live with. Just think though you get to break in during the winter and enjoy much better mileage by the summer.
As I've seen on our Jetta, even at 8K miles (just hit it last night) we're seeing a measured average of 39.18 mpg over the life of the car. This has seen a choppy and steady increase on each fuel up. This is higher than what you see, but living in the south, we've got much nicer temps as well as the fuel is a bit better due to not having to be as robust in guarding against gelling like the stuff found in Canada.
And lastly, welcome to the club!
I don't think there is a clearly defined point which you could say all motors are broken in and you should get the best mileage. It is heavily dependant on how they are driven. I suggested in post 15 to report back at 20k miles (heck at 10K you may see significant improvements). That seems like a lot, but in my 2006 Cummins, I didn't see my best fuel mileage until around 60K miles so diesels do take a long time to break in.
Also as a few other folks have mentioned, you will not get the EPA rating in the winter due to a few factors. Winterized fuel has less energy and colder temperatures creating more drag are the main culprits. Just one of the realizations of winter that we have to live with. Just think though you get to break in during the winter and enjoy much better mileage by the summer.
As I've seen on our Jetta, even at 8K miles (just hit it last night) we're seeing a measured average of 39.18 mpg over the life of the car. This has seen a choppy and steady increase on each fuel up. This is higher than what you see, but living in the south, we've got much nicer temps as well as the fuel is a bit better due to not having to be as robust in guarding against gelling like the stuff found in Canada.
And lastly, welcome to the club!