[bodtwo]

As it says, lots of comments on best MPG figures, but not a lot on MPG when more aggressive right foot is applied.

Anyone any figures or guestimates?

Just for fun as it's very subjective and driven by a conversation earlier today with a pal looking at swapping his S4 for an S6 but getting 12mpg on a weekend test drive (single digit on pushing it 15mpg on a run.)

Cheers

[NISFAN]

Originally Posted by bodtwo

As it says, lots of comments on best MPG figures, but not a lot on MPG when more aggressive right foot is applied.

Anyone any figures or guestimates?

Just for fun as it's very subjective and driven by a conversation earlier today with a pal looking at swapping his S4 for an S6 but getting 12mpg on a weekend test drive (single digit on pushing it 15mpg on a run.)

Cheers

Ask Tengocity about 335d figures when nailing it. I'm sure he reported single digit figures on a track day.

[snipnoob86]

hard to distinguish really on british roads. these cars are so quick the foot is not on the floor for very long before the next corner comes up.

my 335d gives a worthy 20 to 25mpg when absolutely thrashed.

have seen one or 2 on the forum report as low as 11/12 mpg on track.

pressing on but not absolutely caning returns a respectfull 30 to 35 mpg

[Chris330]

I'm getting 28 mpg on my 435i with a heavy foot which I don't think is too bad considering the type of acceleration and breaking I'm doing

[Tengocity]

Yeah on a track day I had it below 10mpg!

My average for first 50000 miles has been 36mpg and thats lots of using it in sport mode for everyday driving. For last 6 months I've been using it as a business tool and lots more longer motorway journeys and I've averaged 38mpg over that time.

But this for a tourer, which is heavier and less aerodynamic than a coupe/saloon, and I also have a remap which I think has a detrimental effect when really driving hard.

If I went for a 1 hour A/B road blast in Sport plus the whole way, then on the public road I'd expect 28-32mpg.

[Firaxis]

Originally Posted by Tengocity

Yeah on a track day I had it below 10mpg!

My average for first 50000 miles has been 36mpg and thats lots of using it in sport mode for everyday driving. For last 6 months I've been using it as a business tool and lots more longer motorway journeys and I've averaged 38mpg over that time.

But this for a tourer, which is heavier and less aerodynamic than a coupe/saloon, and I also have a remap which I think has a detrimental effect when really driving hard.

If I went for a 1 hour A/B road blast in Sport plus the whole way, then on the public road I'd expect 28-32mpg.

I get 36MPG in a sedan (335D), but I use the throttle like a football. I have tried to be super good in Eco-Pro mode on the M-way and got 41.5 MPG. Then got so bored of doing that it went down to 34 ..

It might ease up in a couple of thousand miles??

[Randolph13]

mainly country roads a bit of open motorways in Sport 34 in Comfort 37, haven t done enough Sports + yet to comment

[....,,,,..,,..]

Summer / warm weather run to Anglesey from Wolverhampton, over about five trips varies between 29mpg and 32mpg.

If I go via Chester (M6 etc) and drive sensibly I can get 50mpg.

However, it's also totally fucking boring.

[Tengocity]

But this is the great thing about a performance diesel... In the public road you can cane it as much as you like and still get close to 30mpg. When I did that in the Z4 or even my old mx5 I'd barely get 20mpg.
Or I can cruise at 120mph on the autobahn and get 300 miles from the tank. Do that in a performance petrol and its maybe two thirds that.
Over my annual mileage it's a massive difference.

[AlanYoro35i]

Originally Posted by Chris330

I'm getting 28 mpg on my 435i with a heavy foot which I don't think is too bad considering the type of acceleration and breaking I'm doing

No flipping way!! i drive 80% motorway m3 to earlscourt and i only get 26.7 MPG, and that is granny driving!!

[Daftasabrush]

When nailing it, I'll see 8-14mpg, when driving what I would call 'enthusiastically' I would estimate 20-22mpg. My average is around 26 but that includes a few short runs interspersed with 'enthusiastic' driving periods and the odd motorway run.

[ajfoggy]

Originally Posted by AlanYoro35i

No flipping way!! i drive 80% motorway m3 to earlscourt and i only get 26.7 MPG, and that is granny driving!!

Mine is 29.2 and that is driving up and down the east lancs.

So upto 60 stop, 60 stop all the way. Mostly heavy foot.

So matches mine roughly

[HighlandPete]

Originally Posted by bodtwo

As it says, lots of comments on best MPG figures, but not a lot on MPG when more aggressive right foot is applied.

Anyone any figures or guestimates?

Just for fun as it's very subjective and driven by a conversation earlier today with a pal looking at swapping his S4 for an S6 but getting 12mpg on a weekend test drive (single digit on pushing it 15mpg on a run.)

Cheers

Interesting topic.

We'd really need a 335d and 340i taken through the same heavy test cycles and get some real figures. It is a shame the motor mags don't seem to do that so much any more. It is so easy to say a diesel will give xxx mpg driven hard and petrol yyy mpg, but we all have different baselines.

I'm curious if the mpg gap closes between the two fuels, with harder driving. There are valid reasons to believe they should. The BSFC gap typically closes with engine load on the two fuel types, plus diesel engine efficiency drops with high load/rpm as the petrol typically improves on efficiency. Therefore we'd not expect a similar mpg percentage drop for both engines when driven hard.

A bit of food for thought, the following was reported by AutoCar a few years back in their road tests. Probably about 2006.

Road test mpg figures for 535d vs. M6 (as examples).

535d combined 35.3mpg… road test 13.2mpg
M6 combined 14.8mpg… road test 11.1mpg

I can’t imagine AutoCar giving the M6 any less a hard time than the 535d, so make of it what you will.

[bodtwo]

Its an interesting area, logic told me to buy diesel as I'm doing 20k plus a year and 80% of that on motorways. I sit with ACC on at 75 as I'm driving for work, but I've found myself leaving the m'way earlier and earlier to go point to point cross country as I'm enjoying driving again.

I guess in a year or so I'll tot up all my fuel receipts and work out my mpg.

[jnismith]

I think that one of the big differences in mpg, is whether you drive in comfort or sport (to me, sport + or eco plus don't seem to make any difference).

I'm going to try an experiment today. Drive to where I volunteer (I could say work), in comfort, and back in sport. Very unscientific but I'm interested in what the difference is. My overall average is 39.7 ('63 335D).

[Cootie]

On my favourite stretch of road through the Borders and driving very briskly I'm looking at around 25mpg over a 100 mile round trip.

[jnismith]

Well I tried Comfort in the morning and Sport in the afternoon and was very surprised

Comfort 33.0 mpg at average speed of 29.6 mpg
Sport 32.1 mpg at average speed of 33.6 mpg

Not nailing it but going as quick as I could given the traffic

Surprisingly small difference

[Tengocity]

Originally Posted by jnismith

Well I tried Comfort in the morning and Sport in the afternoon and was very surprised

Comfort 33.0 mpg at average speed of 29.6 mpg
Sport 32.1 mpg at average speed of 33.6 mpg

Not nailing it but going as quick as I could given the traffic

Surprisingly small difference

Try it tomorrow the other way round and let us know!

[gIzzE]

I have had a few of the same cars with the diesel and the petrol engine in over the years.

1.8i A4 vs 1.9tdi = 26mpg and 48mpg.
318i E46 vs 320d E46 = 32mpg and 36mpg (autos)
E320 vs E350cdi Mercedes estates = 28mpg and 33mpg
530d vs 530i e39 = 30mpg and 28mpg
3.2fsi vs 3.0tdi A6 Quattro Avants = 28mpg and 32mpg

535d sport touring was swapped for a 335i sport touring, the 5 I know is heavier, but the 535d averaged 27mpg over the year and 20k miles where as the 335i average 28mpg.

I had the 330d sport touring auto (e91) for just over a week and that was returning 33mpg, which just wasn't worth it compared with the 335i imho.

The other thing was all the petrols were better than the diesel going into Norwich on a morning, which is 11 miles.
Also, our place up at the North Norfolk coast was 45 miles door to door, it was only after 30 miles that the diesels started to over take the petrol MPG wise.
That is when a diesel makes sense, if you do lots of 30+ mile journeys.

On my drive back and forth from just outside Norwich to Cavendish Square in the West End and back again I used to get the following.

335i 37mpg
535d 34mpg
3.2fsi 34mpg
e320 34mpg
e350cdi 37mpg
530d 35mpg
530i 33mpg

320d E91 auto touring 46mpg
X3 xDrive20d auto 44mpg



I think the problem for many is when they buy a petrol they drive it differently to when they buy a diesel. When I used my M3 as a daily for 4 months the average mpg went from 19 to 31mpg.

[gIzzE]

I always wanted to see a genuine 33% gain to make a saving doing 30,000 miles a year, and and was often very disappointed with the diesel figures.

Using BMW Norwich's 330d sport touring for 3 days I was averaging 35mpg, that was pretty much my normal driving. I reckon I would see 30mpg+ from the 340i.

I now do 15k miles a year and that is £43 a week in fuel in the 340i and £37 a week in the 330d. £6 a week fuel saving on a car that is depreciating at £500 a month, and costing another £300 a month servicing, insurance and at the pump is such a small saving that it really is a nonsense to try and justify going diesel.

Buy the diesel if you prefer it, but I think you're kidding yourself if you think it is saving you any money.

The big difference is when you buy at say 5 years old, on a car that is down to £15k and depreciating at only £150 a month, it makes more difference, but still, is it really a deal breaker?

[gIzzE]

One more thing.

Hehe, feel like Columbo.


I got figures for a 340i Sport Touring and a 335d Sport Touring recently, and through Lombard the 340i came in at £46 a month less than the 335d.

£378 a month for the 335d with 4k down and £332 for the 340i.

So, in reality, once you have filled up the 340i is the cheaper car to own overall.


Edit: before anyone asks, the 330d was even more money, less discount and a residual set at some £3k lower than the 335d and 340i.

[JNW1]

Originally Posted by gIzzE

I always wanted to see a genuine 33% gain to make a saving doing 30,000 miles a year, and and was often very disappointed with the diesel figures.

Using BMW Norwich's 330d sport touring for 3 days I was averaging 35mpg, that was pretty much my normal driving. I reckon I would see 30mpg+ from the 340i.

I now do 15k miles a year and that is £43 a week in fuel in the 340i and £37 a week in the 330d. £6 a week fuel saving on a car that is depreciating at £500 a month, and costing another £300 a month servicing, insurance and at the pump is such a small saving that it really is a nonsense to try and justify going diesel.

Buy the diesel if you prefer it, but I think you're kidding yourself if you think it is saving you any money.

The big difference is when you buy at say 5 years old, on a car that is down to £15k and depreciating at only £150 a month, it makes more difference, but still, is it really a deal breaker?

I echo your sentiments entirely! I know there are people who say the large diesels (330d/335d) return much better mpg than a 340i and I don't doubt they are genuine in that belief. However, based on experience with other petrols I'd also be confident of averaging over 30 from a 340i (driving normally, not like a granny!) and bearing in mind I get "only" 38.5 from my 335d that doesn't strike me as a difference to get excited about. I bought the 335d for a combination of the expected range and the potential benefit of X-Drive but after 25k miles and knowing what I know now it would be a 340i for me if I was choosing again. Not saying the 335d is a bad car - far from it - but just feel that for me the 340i would offer more of what I want most of the time.