Am I being daft? 530d vs 540i vs M340i for lots of miles!
Discussion
Hello,
I recently got a new “work from home” job and was really looking forward to buying an F-Type R with total disregard for fuel economy. As it turns out, I do a lot of driving for my new job (consulting), though it is all expensable at 45p/mile. I am currently driving a 500 mile round trip every week, so probably a consistent 20-25k miles/year.
I am coming from a 2021 Corolla (34k miles in 16 months!) which will go to the girlfriend, but I can’t give up the adaptive cruise and lane keeping assistant, they just take all the sting out of 4hr drives. Having test driven an E350d, 530d, and ES300h I loved the engine in the BMW and think the 3 and 5 series estates are very good looking so I am leaning heavily in that direction. Wanted to try and Audi but my local dealer never got back to me.
The issue is, I am not convinced diesel is actually much cheaper anymore, even for mega-miles. Yes you get:
• more MPG
• longer range (nice)
But they’re also:
• Less reliable now with all the emissions stuff (ERG, DPF)
• Probably deprecate faster as people are getting more nervous about a ban and additional city charges (I know this wont happen with modern ones being very clean, but that doesn’t seem to be helping used prices)
• Diesel is now 10-15% more expensive than petrol (that gap potentially growing with Russia controlling a higher proportion of diesel refineries)
So then I started looking at the petrol versions of the 5 series, which naturally progressed to the m340i…..am I kidding myself that the M340i with mostly motorway driving at 75mph will only cost <£120 more a month in fuel? If so, I wouldn’t be surprised if the diesel deprecation is now more than that.
Workings below, assumes 25k miles per year, and fuel prices of £1.40 (petrol) and £1.60 (diesel).

Oh, and while we are on the topic, the 840i looks like very good buying in the second hand maket at the moment...
I recently got a new “work from home” job and was really looking forward to buying an F-Type R with total disregard for fuel economy. As it turns out, I do a lot of driving for my new job (consulting), though it is all expensable at 45p/mile. I am currently driving a 500 mile round trip every week, so probably a consistent 20-25k miles/year.
I am coming from a 2021 Corolla (34k miles in 16 months!) which will go to the girlfriend, but I can’t give up the adaptive cruise and lane keeping assistant, they just take all the sting out of 4hr drives. Having test driven an E350d, 530d, and ES300h I loved the engine in the BMW and think the 3 and 5 series estates are very good looking so I am leaning heavily in that direction. Wanted to try and Audi but my local dealer never got back to me.
The issue is, I am not convinced diesel is actually much cheaper anymore, even for mega-miles. Yes you get:
• more MPG
• longer range (nice)
But they’re also:
• Less reliable now with all the emissions stuff (ERG, DPF)
• Probably deprecate faster as people are getting more nervous about a ban and additional city charges (I know this wont happen with modern ones being very clean, but that doesn’t seem to be helping used prices)
• Diesel is now 10-15% more expensive than petrol (that gap potentially growing with Russia controlling a higher proportion of diesel refineries)
So then I started looking at the petrol versions of the 5 series, which naturally progressed to the m340i…..am I kidding myself that the M340i with mostly motorway driving at 75mph will only cost <£120 more a month in fuel? If so, I wouldn’t be surprised if the diesel deprecation is now more than that.
Workings below, assumes 25k miles per year, and fuel prices of £1.40 (petrol) and £1.60 (diesel).
Oh, and while we are on the topic, the 840i looks like very good buying in the second hand maket at the moment...
Edited by SlightlySlanty on Friday 10th February 10:44
I do a 200 mile trip down from Midlands to Poole once a month. My 340i returns about 41-42mpg for that sat at 75-80.
Closer to home where we are blessed with empty country roads its low 20s.
A diesel did work out cheaper for me (i did similar calcs to you) but its a small price to pay for having the b58 rather than an oil burner!
Closer to home where we are blessed with empty country roads its low 20s.
A diesel did work out cheaper for me (i did similar calcs to you) but its a small price to pay for having the b58 rather than an oil burner!
Edited by Luke H on Friday 10th February 12:50
I suspect the 5 series would be much nicer to cover a lot of miles in.
Or how about a V6 F type for £25k and a £8k diesel car to pile the miles on, with a few k set aside to cover the additional cost of running 2. To be honest, with the reduced depreciation factored in, the cost will probably be the same anyway, if not less?
Or how about a V6 F type for £25k and a £8k diesel car to pile the miles on, with a few k set aside to cover the additional cost of running 2. To be honest, with the reduced depreciation factored in, the cost will probably be the same anyway, if not less?
Hammersia said:
Trouble is £120 here, £120 there, after 3 months you're at £360.
After a year you're at £1440.
After a hundred years you're at £144,000.
It adds up. Kind of like giving up smoking in reverse.
Punting a 340i about is a lot more fun than smoking though, at least for a petrolhead!! After a year you're at £1440.
After a hundred years you're at £144,000.
It adds up. Kind of like giving up smoking in reverse.
Suspect you will only get the 45p rate for the first 10,000 miles- might want to check that.
Depends how much you value a nice petrol engine really, although I think 34mpg is probably pessimistic for a gentle motorway trundle in the M340i. If you other nice stuff for the weekend, I’d probably sway towards the 530d but as a ‘do it all’, M340i.
Depends how much you value a nice petrol engine really, although I think 34mpg is probably pessimistic for a gentle motorway trundle in the M340i. If you other nice stuff for the weekend, I’d probably sway towards the 530d but as a ‘do it all’, M340i.
SlightlySlanty said:
Hello,
I recently got a new “work from home” job and was really looking forward to buying an F-Type R with total disregard for fuel economy. As it turns out, I do a lot of driving for my new job (consulting), though it is all expensable at 45p/mile. I am currently driving a 500 mile round trip every week, so probably a consistent 20-25k miles/year.
I am coming from a 2021 Corolla (34k miles in 16 months!) which will go to the girlfriend, but I can’t give up the adaptive cruise and lane keeping assistant, they just take all the sting out of 4hr drives. Having test driven an E350d, 530d, and ES300h I loved the engine in the BMW and think the 3 and 5 series estates are very good looking so I am leaning heavily in that direction. Wanted to try and Audi but my local dealer never got back to me.
The issue is, I am not convinced diesel is actually much cheaper anymore, even for mega-miles. Yes you get:
• more MPG
• longer range (nice)
But they’re also:
• Less reliable now with all the emissions stuff (ERG, DPF)
• Probably deprecate faster as people are getting more nervous about a ban and additional city charges (I know this wont happen with modern ones being very clean, but that doesn’t seem to be helping used prices)
• Diesel is now 10-15% more expensive than petrol (that gap potentially growing with Russia controlling a higher proportion of diesel refineries)
So then I started looking at the petrol versions of the 5 series, which naturally progressed to the m340i…..am I kidding myself that the M340i with mostly motorway driving at 75mph will only cost <£120 more a month in fuel? If so, I wouldn’t be surprised if the diesel deprecation is now more than that.
Workings below, assumes 25k miles per year, and fuel prices of £1.40 (petrol) and £1.60 (diesel).

Oh, and while we are on the topic, the 840i looks like very good buying in the second hand maket at the moment...
You need ro compare apples with apples the 530d is a couple of steps up from the 3 series with better NVH & a generally nicer interior, so if you were to compare it to anything then it should be the 540i or the 530i.I recently got a new “work from home” job and was really looking forward to buying an F-Type R with total disregard for fuel economy. As it turns out, I do a lot of driving for my new job (consulting), though it is all expensable at 45p/mile. I am currently driving a 500 mile round trip every week, so probably a consistent 20-25k miles/year.
I am coming from a 2021 Corolla (34k miles in 16 months!) which will go to the girlfriend, but I can’t give up the adaptive cruise and lane keeping assistant, they just take all the sting out of 4hr drives. Having test driven an E350d, 530d, and ES300h I loved the engine in the BMW and think the 3 and 5 series estates are very good looking so I am leaning heavily in that direction. Wanted to try and Audi but my local dealer never got back to me.
The issue is, I am not convinced diesel is actually much cheaper anymore, even for mega-miles. Yes you get:
• more MPG
• longer range (nice)
But they’re also:
• Less reliable now with all the emissions stuff (ERG, DPF)
• Probably deprecate faster as people are getting more nervous about a ban and additional city charges (I know this wont happen with modern ones being very clean, but that doesn’t seem to be helping used prices)
• Diesel is now 10-15% more expensive than petrol (that gap potentially growing with Russia controlling a higher proportion of diesel refineries)
So then I started looking at the petrol versions of the 5 series, which naturally progressed to the m340i…..am I kidding myself that the M340i with mostly motorway driving at 75mph will only cost <£120 more a month in fuel? If so, I wouldn’t be surprised if the diesel deprecation is now more than that.
Workings below, assumes 25k miles per year, and fuel prices of £1.40 (petrol) and £1.60 (diesel).
Oh, and while we are on the topic, the 840i looks like very good buying in the second hand maket at the moment...
Edited by SlightlySlanty on Friday 10th February 10:44
If the monthly expenditure is the main priority then the 30d makes sense (I'd ignore trying to look into the future regarding values just accept that whatever you buy will lose value based up your mileage profile)
If we ignore the cost then it all depends whether you value additional space and comfort over the more sporting nature and performance of the M340i, I wouldn't get the 540i though as that is just a thirsty version of the 530d.
If we ignore the cost then it all depends whether you value additional space and comfort over the more sporting nature and performance of the M340i, I wouldn't get the 540i though as that is just a thirsty version of the 530d.
AlfaManc said:
5 Series all the way. Comfort is paramount for 25k miles per year and a 5 Series will devour that mileage.
It's actually swings and roundabouts, I've done up to 35k per year in M3s, 911, M5 as well as more comfortable 520d,740d, 730d etc... they offer a different experience but you can take enjoyment out of all of them, some would prefer the additional feedback of a sportier car some would prefer the comfort and isolation of a barge. Gassing Station | Car Buying | Top of Page | What's New | My Stuff



