[chongyblue]

Hi,

I have a 520d on the way this week and I bought that model for the fuel economy but I am interested in getting real world feedback about a tuning box or other means of remapping to get the best out of the car without it causing problems.

Has any one got one of these devices on an F10 520d and can give real world feedback about the impact on driving performance and MPG?

Any recommendations from experience and can you leave it in place when going to the dealer for servicing with voiding the warranty?

Thanks.