F31 340i Fuel Economy

[Pistonheader101]

Alextodrive said:

In the last few months, I've swapped my 435D Gran Coupe xDrive for an F31 330D Touring xDrive.

The 435D was reasonably quick obviously. Responsive on the throttle and wanted to be driven fast. Well I wanted to drive it fast. Returned me about 30mpg with a mix of urban and motorway. Maybe 35mpg on motorway from memory.

The 330D is quick enough. Doesnt feel like it wants to be driven fast, but can overtake and go when I need to. Its quick off the line when you need / want to be. And it returns me 44mpg on a motorway drive at the speeds youre talking about, with a bit of overtaking and fun on top too. To me it's the perfect all rounder.

The 35D engine just isnt much faster than the 30D in most situations. Sure it'll have an edge and sure it'll pull away over a 30D a little bit. But barely. The extra 50hp doesnt really add enough fun to justify itself in my mind.

I read loads of people saying get the 35D on here. And I get that. More power... is more power. But ultimately a 35D isnt really a properly fast car anyway. So going from 308hp down to 258hp (if my figures are right) really hasnt been all that noticable. Its still plenty quick and does the job.

I'm sure the 340I is lovely to drive and I'll be sure to get one at some point when prices come down, but for me I just cant see the point in having something that returns less than 40mpg on long motorway runs. It's a motorway. It isnt a fun road.

Edited by Alextodrive on Thursday 6th February 00:14

So that would rule out all performance cars. Similar logic would dictate the only car to get is a 318d efficient dynamics.

[Alextodrive]

Pistonheader101 said:

So that would rule out all performance cars. Similar logic would dictate the only car to get is a 318d efficient dynamics.

I think you may have missed my point entirely. Equally it probably wasnt articulated very well.

My 330D gets 44mpg. And my 35D didnt. And I dont dont think the extra 50hp is worth it. It's not that big of a difference. I havent driven a 340I and I'm sure it's lovely, but for me if it isnt returning over 40mpg on motorways and thats what the bulk of the drive is, then I dont see the point.

Personally Id rather have a better cruiser with better mpg and have a properly fun fast car (or even better a bike) for the weekend drives.

But I dont know the cricumstances, and again, those are just my two cents.

No need for the 318D. Lets not be silly.

[b14]

Alextodrive said:

I think you may have missed my point entirely. Equally it probably wasnt articulated very well.

My 330D gets 44mpg. And my 35D didnt. And I dont dont think the extra 50hp is worth it. It's not that big of a difference. I havent driven a 340I and I'm sure it's lovely, but for me if it isnt returning over 40mpg on motorways and thats what the bulk of the drive is, then I dont see the point.

Personally Id rather have a better cruiser with better mpg and have a properly fun fast car (or even better a bike) for the weekend drives.

But I dont know the cricumstances, and again, those are just my two cents.

No need for the 318D. Lets not be silly.

Depends what you want really. For a motorway cruiser your key priority is reasonable MPG, without a significant sacrifice in performance - so makes sense that you might want to get something that has a good balance of the two. For me, I like having a petrol inline 6 - I appreciate the engineering, the power, noise, wide power band, smell of petrol over diesel etc, and prioritise having that over the extra MPG which a 30d or 35d might bring. It's whatever you want, not what someone tells you is best.

[JWH]

Alextodrive said:

In the last few months, I've swapped my 435D Gran Coupe xDrive for an F31 330D Touring xDrive.

The 435D was reasonably quick obviously. Responsive on the throttle and wanted to be driven fast. Well I wanted to drive it fast. Returned me about 30mpg with a mix of urban and motorway. Maybe 35mpg on motorway from memory.

The 330D is quick enough. Doesnt feel like it wants to be driven fast, but can overtake and go when I need to. Its quick off the line when you need / want to be. And it returns me 44mpg on a motorway drive at the speeds youre talking about, with a bit of overtaking and fun on top too. To me it's the perfect all rounder.

The 35D engine just isnt much faster than the 30D in most situations. Sure it'll have an edge and sure it'll pull away over a 30D a little bit. But barely. The extra 50hp doesnt really add enough fun to justify itself in my mind.

I read loads of people saying get the 35D on here. And I get that. More power... is more power. But ultimately a 35D isnt really a properly fast car anyway. So going from 308hp down to 258hp (if my figures are right) really hasnt been all that noticable. Its still plenty quick and does the job.

I'm sure the 340I is lovely to drive and I'll be sure to get one at some point when prices come down, but for me I just cant see the point in having something that returns less than 40mpg on long motorway runs. It's a motorway. It isnt a fun road.

Edited by Alextodrive on Thursday 6th February 00:14

I suspect these are very wise words. Since my original post I've had short drives in both 335d and 340i; usual test drive problems of too short, unsuitable roads and a salesman who quite understandably doesn't want me doing the 'full McRae' on a test drive.

I learn that the 340i sounds lovely, is creamy smooth and goes well when prodded. I liked it very much. HOWEVER, if I'm honest with myself, when it's sitting at 80 on a motorway it's in every way identical to an equivalent 330d bar costing me 30% more in fuel. So no great shocks there.

335d was more surprising. My bottom dyno was of the opinion that is isn't appreciably quicker than my facelift E91 330D. Looking in more detail at various graphs of it's torque curves explains this to some extent by showing that the extra go is really only significant in the upper ends of the rev range. Based on the dynographs on Superchips.co.uk my car averages roughly 540nm between 1800-3000rpm, and an F31 335D averages circa 580nm over the same rev range. The 335d is then capable of holding its torque output further up the rev range, if you rev the pants off it the benefit probably starts to show, but below 3000ish rpm (which is where I spend the vast majority of my time, it's doing almost 114 mph in 6th at 3000 rpm!) there's really not much in it. Once you then consider that the 335d is about 150kg heavier than my car with greater drive train losses it starts to make sense that, in the real world, in average driving conditions, their performance doesn't feel significantly different.

I've included the links below to the graphs from Superchips.

E91 330d https://www.superchips.co.uk/curves/BMW30d245ps.pd...

F31 335d https://www.superchips.co.uk/curves/x35dx40d313PS....

Anyhow, lots of words there but the words of Alextodrive make sense to me. I'm therefore leaning towards stoking the current 330d on with the hope of making 300k miles in it and taking a close look at an M2 as a second car.

[dsgrnmcm]

Thread resurrection!

I have done a painful M5, M4 to London and back in eco pro and got 40.5 mpg. tank to tank calculation. It was terrible.

But doing the same trip but up the A303 in the progressive fashion of the 340i, was 35.6mpg. I did a week of commuting and it was 20 ish.

So you can get 460 miles from a tank, but that is really testing it, boring and not what the car is best at. Awesome car, not going back to the devils fuel....

EDIt: I must have been drunk when I posted this....

Edited by dsgrnmcm on Tuesday 23 November 18:34

[survivalist]

I’ve got a 340i Touring and had a weekend away to see family this weekend. It did high 20s from Hertfordshire to Portsmouth including a couple local trips.

It did have a roof box on, although motorway speeds rarely exceeded 85mph (due to traffic rather than a lack of ambition).

Also always in sport mode, as I find the throttle response in comfort mode depressing.

Slight off topic, but is it possible to code the throttle and steering settings from the OEM Sport settings to be the default ?

[Armchair_Expert]

survivalist said:

I’ve got a 340i Touring and had a weekend away to see family this weekend. It did high 20s from Hertfordshire to Portsmouth including a couple local trips.

It did have a roof box on, although motorway speeds rarely exceeded 85mph (due to traffic rather than a lack of ambition).

Also always in sport mode, as I find the throttle response in comfort mode depressing.

Slight off topic, but is it possible to code the throttle and steering settings from the OEM Sport settings to be the default ?

No - this has been looked at in spades with the 140 / 240's and is factory set.

[AlpinaB5]

I have a 2017 540i X-drive and on a recent trip back to UK averaged 34mpg with the cruise set at 80. For a big heavy 4 wheel drive car I thought that was pretty impressive. The same journey at the same speeds in my Alpina and I get around 26mpg. Over all I am pretty impressed with my 540's consumption. My journey is 502 miles and I had just under quarter of a tank when I arrived. I guess it just depends on how heavy your right foot is

[Comacchio]

Managed 30 mpg on the 10 mile run into work this morning in my F30 340i (With MPPSK) - mix of town driving and motorway albeit stop-start due to traffic levels. On long motorway trips I can get about 42 mpg.