Why Do Euro Diesels Get Such Better MPG's?
 

I have driven a BMW Diesel in Germany and it seems the MPG's were somewhat higher than the US diesels are capable of. Does anyone know exactly why this is? Is it restrictive exhaust emissions? If so, can the US diesels be matched to the Euro ones to get like MPG's? Hypothetically, if one were to remove the CATS where no emmisions testing is required, could the X5 be coded to work with no CATS and achieve better MPG's?

Imperial gallons are larger (by a factor of 6/5) so mpg will always be higher outside of the US. Or were you using litres and converting to US gallons?

Or are you comparing published numbers? If so, the test cycles and adjustment factors applied to the results are completely different.

I wouldn't be removing emissions controls to try and improve mileage.

Converting liters to gallons and KM to miles so it was a true comparison.

They also sell Premium diesel fuel...

It's because Germany has better beer. :)

Well, what were the numbers?