MPG on the diesels???

[DeeTurbo]

Hi all,

I've found the MPG on my 90 e-HDI is awesome when driving at slower speeds but really suffers at 70mph.

What are the 110 e-HDI like at 70mpg or a remapped 90e-HDI?

Just drove back from Bristol and on the way there I got 60mpg driving at 70mph and on the way back I stuck cruise on at 60mph and I got 83mpg, which I was really happy with but I hate driving so slow.

[Syops]

I get similar... Curious on the remap question though...

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[BenS]

Remaps generally improve the MPG a bit but not massively. Many do 2 types of map - eco or power. Eco is obviously more MPG but less power gain and vice versa.

Where it's losing out at 70 is the 5 speed gearbox I think. For my petrol in 5th it's at 3k RPM at 70 mph. However, even at 60 cruising I only get like 47 MPG max so you've got me beat even at 70

[DeeTurbo]

I did wonder about the 6th gear. My 90hp e-HDI revs at 2250rpm at 70mph and is a 5 speed. I wondered if the 6th gear would let it sit at a lower rev at 70mph or is the whole box just closer ratio?

I couldn't do a eco map, it's so slow as it is but a power map still should see a slight increase in MPG is driven sensibly.

My old 306 2.0 HDI sits at 2500rpm at 70mph and I think that achieved around the same or slightly better mpg. I'm thinking the small turbo on my DS3 is probably a restriction above 2k rpm.

[BenS]

The bigger turbo from the 110/115 is definitely worth it for the future, it'll be able to take you to 150 ish. I would have thought the 6 speed would be shorter ratios but have heard of people in the THP getting 90mph in 3rd, and mine only really gets just above 80 in 3rd (on a private track of course). Plus both the 5 speed VTi and the 6 speed THP get to 60mph in 2nd.

I believe the new Performance models have a shorter ratio 6 speed box for better acceleration, but from what I can tell, the normal 6 speed boxes are similar or the same for ratios compared to the 5 speed.

[Howelley]

I've got a stock HDI 115 and 6th gear sits around 2000RPM at 70mph, and 5th is around 2500RPM. If I drive smoothly I can easily get over 60MPG average combined. As for going slow I've seen my car sit around 80-90MPG doing about 60mph. I usually get around 50mpg combined but that's because I have to deal with eastern road and the A27 chichester bypass which really makes me wish I had an automatic!

In 3rd gear I max out around 70mph and between 90 and 100 in 4th (totally on a closed track of course ).