With this being the first Diesel' that I've owned I was keen to work out when is the best time to change gear.

I took a few measurements of RPM at different speeds in the different gears to establish the conversion factors and put together the sheet attached.

As for the colours.  I decided that the minimum RPM the BNV engine is comfortable at is 1,500 and the maximum I was prepared to rev it to is 3,750; and formatted accordingly.

 

I decided that on a flat road, changing up and down on the ten miles-an-hour has sympathy for the car, gives reasonable economy and performance.

 

'hope somebody else finds it useful.

 

         Jim

Roomster_1.4TDI_80-RPM_to_Speed_Converter.pdf

An interesing project Jim, and I agree with most of your findings. I do find it slightly frustrating that the engine isn't really happy at 30mph in 4th except on flat roads and if you want to accelerate quickly, then you have to drop to 3rd. Overall, I'm very happy with the performance and it's a lot better than I expected after reading some reviews before I bought it.

Mike.