Economy

[Welshbeef]

Well this morning I commuted a nice 287 miles average speed 66mph and amazingly average mpg was .... 54.6mpg

Car 231bhp 330d auto with climate on all the time.

How some people can only get low to mid 40's from 2ltr tdi's really is beyond me. Probably something wrong with the cars or driving style hasn't adapted to get the most out of the tdi.

For me the learning is leave cruise control on whole journey.

[soda]

A long trip always helps though, I've seen 52mpg on mine (184bhp manual) over a 600mile trip 4 up with a full boot.

Never normally see over 45mpg though during my normal type of driving.

[roachcoach]

Cruise control is a bit cack handed - if you're trying, you can better it.

Try it, you'll be able to


It does depend a lot on the flow of traffic, iirc my personal best was 56-57mpg for a 20 mile drive to work in my rav4 - not bad for an AWD box

[JungleJim]

my 2-litre tdi has a lifetime average (on the trip computer, so take with a pinch of salt) of 44mpg.

Having said that over a tankful (~700 miles) i did verify it to be ~44.5mpg by manual calculation.

Evidently I haven't learned how to drive a tdi optimally.

[Face for Radio]

People that complain about economy in their cars are usually those that treat the throttle and brakes like on/off switches.

It's easy to get surprisingly good economy from cars if you try.

[Pablo16v]

My Saab 9-5 3.0tdi is averaging 37mpg on a 54 mile round trip commute on twisty country roads, which I'm not happy about

I'm desperately trying to get it down to under 35 but it just won't do it!

[zakelwe]

http://www.zen141854.zen.co.uk/mpg.jpg

That's after being superchipped as well. The skins of rice puddings are still not quaking through the land though

Max I have seen is 81+ over 28 miles.

[waterwonder]

I think you're forgetting that motorway work is often when a car is at it's most efficent hence why extra urban is always the highest quoted offical MPG figure.

This is especially true if you are able to leave the CC on the for the whole journey which implies you were able to stick to a nice steady speed which also helps a lot. I had a fabia diesel which used to do 45-50mpg on the motorway, even at a steady 90 leptons.

Drive your BM across London or even round the M25 on a friday afternoon and i bet you'll be back in the 40-50mpg range.

[Toro Rosso]

DPF - stangles the engine and uses more fuel to clean it.

Also BMW dervs are very good, particularly whilst cruising.

[5lab]

compare that figure to what you'd get out of a 320 ed (I think its ~80mpg extra urban). people get 45mpg by driving in stop/start traffic, or at higher speeds on the motorway

the 3 series is also quite a bit smaller than a lot of 2 litre cars. A mondeo for example has good room for 5, and a large boot, whereas a 3 series (especially the coupe) is compromised in the back and in the boot - the passenger\luggage dimensions are probably much closer to a focus, if not smaller

Edited by 5lab on Tuesday 14th June 13:31

[V88Dicky]

Face for Radio said:

It's easy to get surprisingly good economy from cars if you try.

Very true. Gentle-but-keeping-up-with-traffic driving style is seeing my weekly average at 46mpg for a total of 280 miles of mostly DC.

10 year old, 2.0 petrol BTW

[Monty Python]

Same here - 70mph, cruise/climate control on, 50mpg average (unmodified 335d).

[andy-xr]

Speed (I guess drag) really comes into it on the motorway though, I noticed with mine if I eased off 15mph from my normal ideal speed I saw around 10-15 extra mpg

[McSam]

andy-xr said:

Speed (I guess drag) really comes into it on the motorway though, I noticed with mine if I eased off 15mph from my normal ideal speed I saw around 10-15 extra mpg

Absolutely. The power needed increases (at motorway speeds reasonably accurately) with the cube of the speed. So if you want to do 85mph rather than 70, you'll need 1.8 times the power.

[roachcoach]

McSam said:

andy-xr said:

Speed (I guess drag) really comes into it on the motorway though, I noticed with mine if I eased off 15mph from my normal ideal speed I saw around 10-15 extra mpg

Absolutely. The power needed increases (at motorway speeds reasonably accurately) with the cube of the speed. So if you want to do 85mph rather than 70, you'll need 1.8 times the power.

That's odd, or more specifically surely only part of the picture as my car gets VERY similar fuel economy at 70--85

[Welshbeef]

I can confirm it was cruise set to 70mph - a work trip so no need to go any faster.

Id estimate c50miles of that trip was non M way but clearly still good average speed.

The other thing is music wasnt on too loud (too early really for that) engine I didnt notice it at all / couldnt hear it only the tyre noise. You'd only know it was a diesel by looking at the rpm counter and also the mpg guage.

Glad too I have the auto - twisted ankle last night - would have been 500+ gear changes possibly double that instead effortless changes.

[Steameh]

Cruise control on, steady 60 or 65 will see about 31.5 and 31 respectively on insta fuel.

[Fat Audi 80]

I have seen 60mpg for a 40 mile trip from my Passat 1.9tdi 130, this was grannying it beyond belief with the aircon off etc.

I can easily see 50mpg most of the time if I am careful and do 65 - 70 on the motorway.

Even driving enthusiastically you will see 44mpg on a run.

[pilchardthecat]

How much did it depreciate being a day older and 250 extra miles on the clock?

(Oh god not another fuel economy thread/someone please kill me now)

[Welshbeef]

Fat Audi 80 said:

I have seen 60mpg for a 40 mile trip from my Passat 1.9tdi 130, this was grannying it beyond belief with the aircon off etc.

I can easily see 50mpg most of the time if I am careful and do 65 - 70 on the motorway.

Even driving enthusiastically you will see 44mpg on a run.

Ive yet to have my car below 34mpg over a tank & I drive it properly else Id have got a 316d. I dont sit in London traffic but my commute is 28mph ave speed.... that averages 40-42mpg.