That you will definitely get.I want a more relaxed motorway experience.
I don't know the ratios of the CKR 'box, so can't really comment. Perhaps the gearing is too long and that they're stressing the engine? Perhaps they've increased their speed in order to keep the engine in its peak torque area, thus increasing aerodynamic drag significantly? I don't know how scientific they've been about their measurement, but I'd be very disappointed to have fitted a 6-speed 'box and not be getting an efficiency reward. Certainly everyone I know in the UK with a 6-speed 'box (and there must be at least 40 of them now) has seen either an improvement or no change in economy.but their numbers were definitely on the side of a negative effect.
Ah OK. I get that.
In my case then would just a higher 5th gear work better in my favour do you think?
I have a TDI90
Yes, you can just change the 5th gear. Changing 5th to a 0.659 ratio on a TDI75 looks like this....What kind of money would I be looking at for the 6 speed conversion and is a higher 5th gear ratio available for the TDI90?
Here is the equivalent graph for a TDI90, which already has longer gearing from factory. The black lines show the TDI90's standard 5-speed 'box, the red lines show the same gearbox once covered to 6-speed.
So, a TDI90 turns 2407rpm to get 70mph. That's a lot more than the 1955rpm that I turn in my TDI75 in 6th.
Note that these graphs are for 5-speed gearboxes that have been upgraded to 6-speed. You can, however, fit the MYP 6-speed gearbox to a TDI90 and get the equivalent of the graph in Post 7.
Cheers,
Tom
Curious. @Away with the fairys has a TDI90 with an MYP 'box and gets superb mpg.I fitted a 6 speed box on a TDi 90 and I don’t think I see much difference mpg to be honest, if anything I think it may be slightly worse.