Varying MPG Returns

Hi guys,

I'm wondering if it's common for the HDi engine to throw up such varying MPG returns between motorway and urban driving?

I travel the country following the Swans, so do a fair bit of motorway miles. I can get roughly 48MPG average over a full tank of diesel on the motorway. This is with a full car - myself and either 3 or 4 passengers, so there's a fair bit of load. I imagine I could increase that figure quite a bit if there was less passengers and I reduced my speed a little - so I'm happy with this return.

However, I also work part time as a delivery driver around Swansea. It's literally all stop-start driving, with the engine being turned on and off on average every 3 miles I'd say - Swansea is kinda known for it's amount of traffic lights (which adds to the stop-starting) and is also very 'hilly'. I'm only getting 30MPG, or 33MPG if I take it easy with the revs. Baring in mind that when I'm working and doing these urban miles, there's only myself in the car - so substantially less weight to haul around.


It's a HDi engine. 110,000 miles. Serviced 1,000 miles ago. Using Millers Diesel Power Sport 4 every couple of tanks. Tyre pressures ok. No other performance issues (no lack of power etc.). Figures are based on the brim-to-brim test, not by needle gauging, so they're fairly accurate.


Would you guys say it's common for the HDi engine to perform so poorly around town? I know the above driving conditions do not lend to good fuel economy (in fact, they're probably as bad as it gets), but I still can't help but feel that 30-33MPG is extremely poor. But then at the same time, as I'm getting decent-ish returns on the motorway, it makes me doubt whether there's a fault after all

Any thoughts or suggestions?

Thanks

Sounds ok to me. Average speed on my trip comp when town driving is usually about 18mph.

Sounds right to me also!

My S1 rallye is getting better MPG than ever in the cold weather, but think this is due to the snow/ice forcing me to drive slower

I'm glad to hear that. But you hear claims on forums of people saying they only do urban driving an still get 45+MPG and it makes you wonder

My dad owned a Peugeot Expert with a 2.0 HDi engine up until only a few weeks ago and he was only getting 28MPG. And like me, that was all stop-start driving around the city centre. So it was either a case that both of us had faults causing poor MPG, or simply the HDi isn't as efficient around the town as some people say

Indeed some of these MPG claims on ebay adverts make me laugh.

Thats spot on to what a very close friend of mine gets also

I think that the older hdi units just werent so effective at town driving unless you drive like a saint