C5 HDI Heavy on fuel

[SaabC5]

All you knockers of the 2.2HDi. This was achieved going to Doncaster from London using the A3, M25 and then M1. I didn't use cruise as it uses more fuel than careful pedal work at no more than 60mph. The return journey i did late at night going "slightly" over NSL saw it fall down to 45mpg.

[mooseshaver]

All you knockers of the 2.2HDi. This was achieved going to Doncaster from London using the A3, M25 and then M1. I didn't use cruise as it uses more fuel than careful pedal work at no more than 60mph. The return journey i did late at night going "slightly" over NSL saw it fall down to 45mpg.

Wow is all I can say really

[SaabC5]

I've never got anywhere near that again driving "normally", but it shows what you can do if you practice hypermiling techniques. Accelerate gently, anticipate hills and slowly increase speed prior to them, roll down the other side foot off the gas, keep a sensible distance behind other vehicles to avoid using the brakes. Keep tyre pressures even and tracking correct to minimise tyre scrub losing valuable mpg. It can get quite addictive if you try it seriously.

[mooseshaver]

I just set the cruise and ask the car to wake me up when I get there.

[qprdude]

In perfect, flat road conditions with no traffic, cruise is more fuel efficient as the computer utilises the most efficient use of revs and speed increase to get to the preset cruising speed, far more exact than driving manually, but it is nigh on impossible to have perfect conditions in the UK. Maybe in the American plains, but not on our traffic heavy roads. Of course, it's not possible to go to the ultimate fuel economy driving in an auto gearbox car.

[Jeff]

Agree with Peter N, I know you can get 60 mpg on a run if you drive sensibly as when I got my 2.0 HDI over 3 years ago I brimmed the tank and on a 570 mile round trip that included a road accident delay I refilled and worked out a figure of 60mpg. I was well pleased.

Since then not sure if I still get that as never fill to the brim and I put a new MAF on the car this weekend as the car was lacking power on hills (the car flew up the hill on way home tonight) so fingers crossed my mpg will be higher plus I intend using injector cleaner when I next 1/2 fill the tank which is something i should have tried in the past.

EDIT: also put MAF pipework back on with an extra jubilee clip which was missing on the inlet manifold side. I guess the maf was not gettingan accurate reading with air getting in the inlet side and not passing through the air filter and MAF.Perhaps someoen reading this can advise. (the pipe onto the inlet manifold was loose enough for air to get in).

[qprdude]

Basically, there are too many variables involved to give an accurate answer as to what mpg you get from your car. Road conditions, weather conditions, traffic conditions and especially weight. If you get 55mpg on a solo run , you wont get it with two suitcases in the boot.
The age of the car will also make a difference, as will the lubricant, tyre type and condition. If you can get within 4-5 mpg either way, you will be doing pretty good. Someone who lives in Stafford, and commutes along the M6 toll twice a day, will get a totally different reading from the same engine, if they live in the Scottish highlands and commute for the same distance every day.
I'm also thinking about the figures reported for the 2.2 HDI. Did you all know that the phase 2 cars, 2008> are 70Kg heavier than the phase 1 ?
(According to Citroen there are only 2 Citroen C5's , the 2004> car was a phase 1 facelift. I spoke to a Citroen UK guy this morning about another matter, and that's what he told me)
He said even Citroen garages are calling the cars Mk1, 2 and 3, but there is no Mk3 in reality, only phase 1 and 2.

[imperial21]

I maybe clutching at straws but could my car have a fault with the egr system to make it bad on fuel ?

[Peter.N.]

All you knockers of the 2.2HDi. This was achieved going to Doncaster from London using the A3, M25 and then M1. I didn't use cruise as it uses more fuel than careful pedal work at no more than 60mph. The return journey i did late at night going "slightly" over NSL saw it fall down to 45mpg.

Wow is all I can say really

That is amazing, there is no way I could get that from mine, I can get the sort of consumption and more from the 2.0., whatever it is that's the problem with most of the 2.2s your's hasn't got it. I cant get that sort of consumption driving at 50 mph and at a steady 60 it won't make 50 mpg - can you let me into the secret?

Peter