Short mileages and Diesels - is it really an issue?

[Turkey]

renrut said:

I wasn't actually angling for a replacement, only interested in making sure I wasn't storing up problems for 6 months down the line - prevention is better than a cure and all that; But many have suggested a large petrol engine is the 'sensible' PH option. Perhaps for the next car, we tend to keep cars a good 6 years so this one would be around due for replacement sept 2018 (unless I get bored). Not sure what would be best by then, I've always fancied an XJR or similar big barge, maybe that'll be the opportunity.

Sounds good, yes it was a typical PH response, but I've now got my first petrol in about 10 years and very nice it is too (330i).

[Mr Tidy]

Turkey said:

Sounds good, yes it was a typical PH response, but I've now got my first petrol in about 10 years and very nice it is too (330i).

Nice choice!

2 years ago I saw the light - after nearly 10 years of 2 litre turbo-dieselness I bought a Z4 Coupe! Eureka moment, so now my daily is a 325ti Compact!

Won't ever be buying another diesel unless I need a big van or a tractor!

[Mr Tidy]

Riley Blue said:

We have a 1.4 Fiesta diesel which hasn't been further than a handful miles from home in the past eight years, it hasn't had any problems and is giving 40mpg.

But that puts the whole debate into perspective IMHO.

I had a 320td Compact for 3 years and 42K miles which averaged over 46mpg, followed by a 123d for 6 and a half years and 81K miles with an average of over 48mpg.

Since December 2014 my daily has been a 325ti Compact which has averaged over 32mpg for the 12K miles I have had it. (The On-Board Computer shows an average of 34.5 mpg)!

The 325ti drives so much better than the 320td or 123d that I would never contemplate going back to tractor fuel!

Your 1.4 diesel Fiesta may not have broken (yet), but 40mpg is abysmal - I'm sure a 1.4 petrol Fiesta would do at least as well for the same use, which does seem to confirm that "Short Mileages and Diesel" really is an issue!

[lord trumpton]

Just see how the new job pans out for a while before making any big motoring decisions. You may not like the job or get fired or whatever. Review in 6 months and see how the car is performing and whether you still want to work there etc.

[Jiebo]

Howard- said:

Diesels take longer to warm up than their petrol counterparts. Over a 4-mile commute, I'd say the majority of that would be spent with the engine operating fairly inefficiently and, thus, the difference in MPG between it and an equivalent petrol will probably be much smaller than you'd think.

Added to the fact that, IMHO, most 4-cyl diesels are pretty horrible and inflexible in town-driving conditions, I'd be changing for a petrol if it were me.

People say this a lot, but it's not true in my experience.

I used to drive a an old VW Mk5 Golf 2.0TDI, and when pottering around town, stop starting when cold it use to do 35-40mpg.
Compare this to the 1.6/1.8/2.0 petrol and that would be closer to 25 when cold.

The argument is valid for DPF's because they get ruined. But MPG's is not a valid point, unless you're comparing to a long motorway run or something?

[Jiebo]

Mr Tidy said:

But that puts the whole debate into perspective IMHO.

I had a 320td Compact for 3 years and 42K miles which averaged over 46mpg, followed by a 123d for 6 and a half years and 81K miles with an average of over 48mpg.

Since December 2014 my daily has been a 325ti Compact which has averaged over 32mpg for the 12K miles I have had it. (The On-Board Computer shows an average of 34.5 mpg)!

The 325ti drives so much better than the 320td or 123d that I would never contemplate going back to tractor fuel!

Your 1.4 diesel Fiesta may not have broken (yet), but 40mpg is abysmal - I'm sure a 1.4 petrol Fiesta would do at least as well for the same use, which does seem to confirm that "Short Mileages and Diesel" really is an issue!

If you drove your 325i around town when cold for 4 miles you wouldn't even get 20mpg, right?

[gazza285]

Jiebo said:

If you drove your 325i around town when cold for 4 miles you wouldn't even get 20mpg, right?

True. The wife had a Volvo 2.4t V70, that averaged 21mpg with her driving to work and back, the D5 replacement does 43...

[Sheepshanks]

Jiebo said:

The argument is valid for DPF's because they get ruined.

The latest VW DPFs never passive regen - they do a forced one typically every 200 miles. The only problem would be that it takes about 10 mins so if you only did short journeys the regen cycle might never complete and you'll start to get dpf clogged warnings.

[raspy]

renrut said:

I'm changing jobs in a month and my commute will drop to only 4 miles each way and it got me thinking - do diesels still have issues with short mileages? The car is thankfully pre-dpf as I know they have issues, but what about those without them? And what about petrol cars? How are they for shortish mileages?

The car will still be used everyday but it won't be doing much in the way of mileage, maybe 4k per year.

Obvious solution is a silly hybrid / EV but I think I could only do that for something very quirky - mk1 Insight in green please!

I did 4 miles in my Prius today. Got 85mpg.

[rainmakerraw]

Jiebo said:

If you drove your 325i around town when cold for 4 miles you wouldn't even get 20mpg, right?

Really? Different marque but my 2.0 TSI Superb (not a small car) is in the early 30s MPG from stone cold by the time it's done its first mile. By the time it's done 4 miles I'm knocking 40mpg, and mine is a more powerful engine than the 325i.

[Jiebo]

rainmakerraw said:

Really? Different marque but my 2.0 TSI Superb (not a small car) is in the early 30s MPG from stone cold by the time it's done its first mile. By the time it's done 4 miles I'm knocking 40mpg, and mine is a more powerful engine than the 325i.

Yeah, computers over-read buddy. You get 25ish in the winter and maybe 28 max now in the summer, on these cold trips. You haven't got a special car, it's just how petrol engines work.

[rainmakerraw]

Jiebo said:

Yeah, computers over-read buddy. You get 25ish in the winter and maybe 28 max now in the summer, on these cold trips. You haven't got a special car, it's just how petrol engines work.

My OBC is within 0.5mpg of actual brim-to-brim as it happens, and 90% of my journeys are local and from cold. I still get mid to late 30s MPG brim to brim. I don't profess to have a special car, I just questioned why it was automatically assumed the other poster's 325i would be poor on fuel when most modern petrols are rather good. In fact I spend less on fuel now I have a petrol than I did when I had 2.0 TDIs, though as I said I do mostly local journeys.

Also it's rather strange to confidently assert that I get 25ish in winter and maybe 28 max in summer. In what? A 0.9l NA or a 3.6 turbo?...

[Jiebo]

rainmakerraw said:

My OBC is within 0.5mpg of actual brim-to-brim as it happens, and 90% of my journeys are local and from cold. I still get mid to late 30s MPG brim to brim. I don't profess to have a special car, I just questioned why it was automatically assumed the other poster's 325i would be poor on fuel when most modern petrols are rather good. In fact I spend less on fuel now I have a petrol than I did when I had 2.0 TDIs, though as I said I do mostly local journeys.

Also it's rather strange to confidently assert that I get 25ish in winter and maybe 28 max in summer. In what? A 0.9l NA or a 3.6 turbo?...

The 325i is an old 6 cylinder BMW engine.

I've run a 330i e46 in the past and I full well know that on short trips to the supermarket it couldn't break 15mpg.. I saw about 12-13mpg in the winter.

[chris285]

I have a mk1 leon pd150, and i have worked no more than 2 miles from home over the passed 6-7 yrs and i have never had a problem with the car

EGR issues are due to carbon build up so just needs a decent run from time to time, i think battery could be an issue due to the high draw to start and especially during winter it may not full charge it. But from my experience it is not a problem, i want to change it an get a petrol but can't afford to right now so it is doing me fine

[renrut]

lord trumpton said:

Just see how the new job pans out for a while before making any big motoring decisions. You may not like the job or get fired or whatever. Review in 6 months and see how the car is performing and whether you still want to work there etc.

Sound advice sir - I wasn't planning on doing anything rash - too much going on. Once the obligatory 3 month probation is out of the way I'll know one way or the other.

For all the discussion on mileages I get a sound 40mpg from my 2.2 CRV at the minute over a 12 mile commute.