diesel consumption in town driving

[carlovers]

Guys is there a consensus of opinion that diesels dont like stop start driving and never get warmed up .Reason?I have a 120d auto 7 mths old.On long journeys with motorways thrown in mpg is great 46-53mpg.However i reset OBC drove for 9 miles around outer london postcodes w4 w3 nw10 took about 35 mins .On the OBC showed 21mpg


So is there a case that if you do mostly town driving and you like petrol engines then mpg wise theres nothing in it?

[pgilc1]

carlovers said:

Guys is there a consensus of opinion that diesels dont like stop start driving and never get warmed up .Reason?I have a 120d auto 7 mths old.On long journeys with motorways thrown in mpg is great 46-53mpg.However i reset OBC drove for 9 miles around outer london postcodes w4 w3 nw10 took about 35 mins .On the OBC showed 21mpg


So is there a case that if you do mostly town driving and you like petrol engines then mpg wise theres nothing in it?

I cant see any car being particularly chuffed at stop start driving which leads to an average of around 18mph.

It would be hard to do high mileage and only do round town driving, so i guess that would be the overriding factor

Interesting that pretty much all taxis are diesel and they do mostly round town work and high miles though?

[carlovers]

they do but they only get around 20mpg

[Neil.D]

you wont see much of the benefit of a diesel around town as you say.
the only benefit of a derv is the added low down torque which may reduce the temptation to rev - maybe keeping fuel use down.

[Welshbeef]

To be fair youd need to have done the same identical journey with a petrol of similar performance otherwise in isolation your 21mpg is meaningless.

[Ranger 6]

Relying on the OBC is only fooling yourself, on the Golf the OBC was sometimes up to 15mpg out and the BMWs are between 6-12mpg out - both too high and too low sometimes.

If you want to measure it then start running some sort of record (spreadsheet?) with actual fuel used and distance covered. You will be suprised.

[Welshbeef]

My Golf was accurate - Mk4, well under 1mpg different.

If your golf was 15mpg out on the OBC - did you take it back to get it repaired?

[Ranger 6]

So you run a spreadsheet too then

Didn't bother with the golf, it was out of warranty and I knew from the records what mpg it was doing.

[Welshbeef]

Ranger 6 said:

So you run a spreadsheet too then

Didn't bother with the golf, it was out of warranty and I knew from the records what mpg it was doing.

What was the model & what was the MPG?

Mine was a GT TDI 115 5 door which got roughly 55-65mpg all the time.

[Neil.D]

Are all diesel drivers the same? Spreadsheet? Geeeeze, LOL

Edited by Neil.D on Wednesday 1st October 12:07

[Ranger 6]

Welshbeef said:

Mine was a GT TDI 115 5 door which got roughly 55-65mpg all the time.

So was mine and over three years and about 35k miles I think it was 42mpg. But if you want it exactly you'll have to wait until I get home;)

Neil.D said:

Are all diesel drivers the same? Spreadsheet? Geeeeze, LOL

I do it for the petrol car too....

[gizlaroc]

Diesels are crap on short journeys, they take ages to get to temp.
Plus you have an auto so the torque convertor is constantly sapping power too.

My 120d auto used to return around 26mpg doing purely short town work, the 320d was a little better at just over 30mpg, our older A3 DSG used to be about 30mpg too, A6 Multitronic was about 26mpg.

In comparison 530i auto was 24mpg, 335i auto 23mpg, E320 estate 22mpg, M3 SMG 21mpg.


I won't buy a manual diesel and I don't do alot of motorway miles sat at 65-70mph either, which is the only way to get good consumption, so I have given up with them.

My E320 estate does 35mpg sat at 85mph, the M3 does 32mpg sat at 85mph, even the efficient dynamics 320d which is meant to be one of the more efficent disels ever made, only does 39mpg sat at 85mph.

Yeah diesels can work for some people, but you have to be very strict with yourself regarding speeds etc.

I get too bored to worry about it any more, in a petrol I just drive and think 'sod it!' where as in a disesl I am always watching the OBC!!

So petrol it is for me!

[gizlaroc]

Thinking about this more and reading other posts, like the 530i mpg one, I think it has got more to do with how people drive them, in petrols people enjoy it more, like revving it and that is why petrol consumption is a lot lower when people compare figures on these boards.

The diesel driver doesn't get the same pleasure, none of that 7000rpm, no lovely noise, just a clatter and a heavy front end to fight against, so they have to look for fun elsewhere, so they play the "oooh, let's reset the OBC again whilst crusining at 56.6mph and see if I can keep it at 99.9999mpg for the whole journey!!"

Wooopeee fukin'doo!! Pass me the noose!!


I am of course joking before anyone starts to have a pop. But at the same time I know how I drive them both, and I do think there is a bit of thruth in there.

The 320d I always tried to get good mpg from, same with the 1.9tdi and 2.0tdi Audis, of course the 535d just got ragged as the shove was exciting, but then over 40k miles it was only showing 25.9mpg. So I think that it is more about the driver than the fuel.

[carlovers]

gizlaroc interesting stuff.Nice to be in a position to put words into action.Trouble for me is that i do 35000 miles a year,and on long journeys giving it a lot of stick i get 43mpg, doing 70 ill get in the 50s and thats handy;)

[dibbly_dobbler]

carlovers said:

Guys is there a consensus of opinion that diesels dont like stop start driving and never get warmed up .Reason?I have a 120d auto 7 mths old.On long journeys with motorways thrown in mpg is great 46-53mpg.However i reset OBC drove for 9 miles around outer london postcodes w4 w3 nw10 took about 35 mins .On the OBC showed 21mpg


So is there a case that if you do mostly town driving and you like petrol engines then mpg wise theres nothing in it?

I agree that seems poor - In my 130 I'm averaging about 21mph on my current tankful with mpg approx = 27.

It'll only do mid 30s on a run though !

[tali1]

carlovers said:

Guys is there a consensus of opinion that diesels dont like stop start driving and never get warmed up .Reason?I have a 120d auto 7 mths old.On long journeys with motorways thrown in mpg is great 46-53mpg.However i reset OBC drove for 9 miles around outer london postcodes w4 w3 nw10 took about 35 mins .On the OBC showed 21mpg


So is there a case that if you do mostly town driving and you like petrol engines then mpg wise theres nothing in it?

All my journeys are town driving - and the MPG gets hit HARD.Currently i have a Pug 307 1.6 auto - 18mpg,THese are my previous over last 16yrs.REAL world figures- not fantasy land "my v6 does 30mpg around town bks"
23 mpg -94pug 405td
22mpg -87mg montego turbo
18-22mpg -83toyota camry 1.8
17-mpg -91citroen ax gt
17 mpg -80 toyota starlet 1.2
16mpg -85montego 1.6
15mpg -99mondeo 2.0auto (with a very accurate OBC)
On rare motorway trips MPG improved on most by 40-50%

[carlovers]

Tali ,they are quit frightening figures wonder what say the 645i doing your journeys would do. Chatted to a bloke in a petrol station admiring his R32 said to him "what do yo get around town about 20 " he said, he wished ,more like 16.

[tali1]

carlovers said:

Tali ,they are quit frightening figures wonder what say the 645i doing your journeys would do. Chatted to a bloke in a petrol station admiring his R32 said to him "what do yo get around town about 20 " he said, he wished ,more like 16.

Those figures are just pottering around town- no roof racks, A/C or heavy loads-people say it's my driving - but how bad can i drive persistently for 16 yrs?- my driving is exactly same as any others with good MPG figures -it's lucky i only do 4000miles a year
Friend had 1989 Golf gti 16v -18mpg.Another has an BMW X5 3.0i -he gets 14MPG.
Had a new 200SX for a week -14MPG.Weirdly, thrashed nuts off a brand new Toyota Landcruiser 4.5 V8 with lots of stuck in traffic (11mpg urban claimed) - and incredibly the fuel guage barely moved!

[Ranger 6]

Good one tali - shows the variance. have now dug out the details from my records (and realise what a complete saddo I've been for saving these details for the last 8 years!!)

These are actual mpg figures, not OBC, showing the miles covered and average mpg over those miles, starting in May 2000 when I bought the Volvo and my wife had the Polo;

Volvo V40 2.0 - 33k Miles - 30.306mpg
Merc C220 CDi(T) - 16k Miles - 38.915mpg
Merc ML320 - 2k miles - 19.537mpg (sold it 'cos it was crap)
VW Polo 1.4 - 43k miles - 40.384mpg
'01 320d touring - 21k miles - 37.591mpg
'03 320d touring - 8k miles - 37.776mpg (written off)
Golf GT TDi 115 - 45k miles - 41.576mpg
911 C4 Cab - 7k miles - 19.4mpg
X3 2.0d - 28k miles - 30.983mpg (still got it)
130i - 2.5k miles - 24.118mpg (only just got it)

...and I've got cost per mile including depreciation amongst others