Temp doesn't go above 80 DegC (320 CDi)

[mr. shr]

How do you know how much to put in? Is there a level indicator?

 

[markmifsud]

theres a level mark on the header tank

 

[Satch]

Following a good run yesterday, I can report that the fuel efficiency has definitely increased, and quite noticeably too.

We have been doing a regular run up to Sheffield in recent weeks (every Saturday) and I have always put the cruise on 70mph and let the car drive there itself.

Recently, I have averaged about 35-36mpg on this run with the temp gauge on 70C.

Yesterday I did 42mpg with the temp gauge on 85C, which is definitely back to normal.

The gearbox shifts seem smoother to me now too, but I can't explain why that might be, so I am putting it down to 'placebo effect'.

Because the heat exchanger for the transmission runs through the radiator, the transmission fluid will also tend to be a bit warmer

 

[corned]

Because the heat exchanger for the transmission runs through the radiator, the transmission fluid will also tend to be a bit warmer

Agreed; but what I don't get is why would that make any difference?

Higher temp = lower viscosity of the atf? Lower viscosity = smoother changes?