Peugeot 307 SW (2002 - 2008) - 04 1.6 Worse than expected 1.6 HDI Economy

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Tue 24 Jun 2008 00:21
04 1.6 Worse than expected 1.6 HDI Economy - CoolRunning
I recntly traded my dear old W reg 306 2.0 HDI Estate for a 54 plate 307 SW 1.6 HDI. I had done 150,000 miles in just over 5 years at an average MPG of about 52 in the 306. It was just edging off a bit lately, possibly due to the turbo getting a bit tired and therefore needing slightly more throttle below 2K revs. I nearly always fill brim-to-brim and it only ever dipped (just!) below 50 on a tankfull on a couple of occasions!
I purposely bought a 1.6 rather than a 2.0HDI coz the economy is supposed to be better on the 1.6. At 30K miles per year & paying for them all myself, I'm quite keen to get the best economy possible. The 307's computer tells me I'm averaging 56-57MPG & I'd be very happy with that, but on measuring what I'm putting in the tank, it's only 48! Exactly the same driving profile as the 306. I tried driving extra-economically on a long round trip of 1700 miles & whereas the 306 would easily have done 55 driving like that, the 307 was still below 50.

Couple of curious things to note. Last week I was very late for a meeting and did 30+ miles at a steady 80. The computer said I was down to average 54.3 on that tank, but filling to the brim again measured a little under 50, ie better than usual!
Also, if driving on minimum throttle, it seems to jerk a little every now and then.

Any suggestions as to any possible problems given the above symptoms. It's still under warranty if I need to get something fixed!

Cheers!
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Tue 24 Jun 2008 01:32
04 1.6 Worse than expected 1.6 HDI Economy - Screwloose

Not exactly an uncommon complaint. Firstly; does 9HY or 9HZ appear in your VIN number?

Secondly; what's the difference in the kerb weight of a 306 and a 307?
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Wed 25 Jun 2008 16:39
04 1.6 Worse than expected 1.6 HDI Economy - CoolRunning
It's a 9HZ, which I understand means that it's got an FAP fitted.

Yes I knew that the 307 is a bit heavier, one reason for the decision to go for the supposedly more-economical 1.6 rather than the 2Litre; but having checked the actual weights, I see that the difference is more than I thought!

Any comments on the symptoms I mentioned, or do I just have to put up with it??
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Wed 25 Jun 2008 17:01
04 1.6 Worse than expected 1.6 HDI Economy - Screwloose
CR

The jerkiness could be a software problem; get the latest version uploaded first.

Small diesels shifting a heavy vehicle aren't that economical. [Something that truck operators found years ago.] A big diesel running slower, on a light throttle, will always win. A Lister Blackstone straight-8 was at it's most efficient at 650rpm.

Your high-speed improvement was due to better aerodynamics and the steady speed - it's accelerating all that weight that kills the consumption figures.

As Government figures are done on rollers, where weight isn't a factor; when comparing with a lighter car, make a due allowance. A DPF will eat fuel too.

Edited by Screwloose on 25/06/2008 at 17:04

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