Diesel BMW but short journeys?
Discussion
Looking or advice on BMW diesel engines and short journeys/low mileage please.
I currently have a 2014 730d which I love, and am planning ahead for when I might get something newer later this year. I would love the newer G11 730d however my annual mileage is low and mostly short journeys which isn't ideal for a diesel. But I would love another 7 Series.
I've read that an Adblue & EGR delete, and swirl flaps removal can help, but this seems excessive to me and MOT's might become a problem in the future if rules change?
I hear that the petrol 7 Series don't have such bullet proof engines and can be costly to run, so hI've also been eying up petrol X5's too, but which engine option would be best for a 7 Series doing low miles & short journeys?
Diesel G11 730d (B57) left as standard and hope for no issues
Above but with deletes
Petrol 740i (B58), 750i (N63), or 760i (N64)?
I currently have a 2014 730d which I love, and am planning ahead for when I might get something newer later this year. I would love the newer G11 730d however my annual mileage is low and mostly short journeys which isn't ideal for a diesel. But I would love another 7 Series.
I've read that an Adblue & EGR delete, and swirl flaps removal can help, but this seems excessive to me and MOT's might become a problem in the future if rules change?
I hear that the petrol 7 Series don't have such bullet proof engines and can be costly to run, so hI've also been eying up petrol X5's too, but which engine option would be best for a 7 Series doing low miles & short journeys?
Diesel G11 730d (B57) left as standard and hope for no issues
Above but with deletes
Petrol 740i (B58), 750i (N63), or 760i (N64)?
No car engine enjoys a short journey. I tend go to the office once or twice a week, it's 12 miles away. My car is only just fully up to temperature when I get there.
B58 is one of BMW's most reliable modern engines, it has very few negatives. Its the only one I'd consider from that list, given your proposed use.
Its still capable of moving a 7 pretty rapidly, and will do mid 30's on a motorway run.
B58 is one of BMW's most reliable modern engines, it has very few negatives. Its the only one I'd consider from that list, given your proposed use.
Its still capable of moving a 7 pretty rapidly, and will do mid 30's on a motorway run.
Yes, the B58 does seem to be the favoured petrol engine across BMW models
I asked chatgpt to compare how the B58 fares versus a diesel 730d for short-trip use and was surprised to read that the diesel fares better than I had thought, basically the diesel engine gets to temperature quicker but its DPF fares worse than the petrols GPF. So swings and roundabouts with some some vehicle sympathy required - Limit short drives (I probably can't) and do some long drives, and on the B58 leave engine running after stopping to allow hot oil to depart the turbo..
I asked chatgpt to compare how the B58 fares versus a diesel 730d for short-trip use and was surprised to read that the diesel fares better than I had thought, basically the diesel engine gets to temperature quicker but its DPF fares worse than the petrols GPF. So swings and roundabouts with some some vehicle sympathy required - Limit short drives (I probably can't) and do some long drives, and on the B58 leave engine running after stopping to allow hot oil to depart the turbo..
Edited by The Gauge on Wednesday 7th January 09:08
That's the current issue with Ai, often a completely different response depending how the questions are constructed.
As for sitting to let the Turbo cooldown. Only, if you've really ragged the nuts off if for a considerable amount of time. I remember doing that on my Cosworths in the 90's, but they did glow red hot due to my driving style at that time..
The B58 (Petrol) Perspective
The B58 is remarkably tolerant of short trips for a high-performance engine. It uses a heat encapsulation system that helps it retain warmth for hours after being shut off, making the "next" short trip less of a cold start.
The Risk: On very short trips, the engine runs "rich" (extra fuel) to heat up the catalysts. If you never reach full temperature, unburnt fuel can seep into the oil (dilution) and moisture can build up in the crankcase.
The Fix: Give it an "Italian Tune-up" (a 30-minute motorway drive) once every two weeks to burn off moisture and carbon.
The B57 (Diesel) Perspective
The B57 is a masterpiece for long-distance cruising, but short trips are its "kryptonite."
The DPF Problem: The Diesel Particulate Filter (DPF) traps soot. To clean itself, it needs to get extremely hot (Regeneration). Short trips don't provide enough heat for "Passive Regen," and "Active Regen" (where the car injects extra fuel to create heat) often gets interrupted when you arrive at your destination.
The Consequence: Interrupted regenerations lead to soot buildup, "Limp Mode," and potentially a multi-thousand-pound bill for a new DPF. Additionally, frequent interrupted regens can cause diesel to mix with your engine oil, raising the oil level and decreasing its lubricating ability.
Summary Recommendation
Choose the B58 (Petrol) if 80% of your driving is around town, school runs, or short commutes. You will pay more in fuel, but you will save thousands in potential maintenance and have a more responsive engine for those short bursts.
Choose the B57 (Diesel) only if you do at least one 30+ minute motorway run every week. If you don't give it that "breather," the emissions systems will eventually fail.
As for sitting to let the Turbo cooldown. Only, if you've really ragged the nuts off if for a considerable amount of time. I remember doing that on my Cosworths in the 90's, but they did glow red hot due to my driving style at that time..
The B58 (Petrol) Perspective
The B58 is remarkably tolerant of short trips for a high-performance engine. It uses a heat encapsulation system that helps it retain warmth for hours after being shut off, making the "next" short trip less of a cold start.
The Risk: On very short trips, the engine runs "rich" (extra fuel) to heat up the catalysts. If you never reach full temperature, unburnt fuel can seep into the oil (dilution) and moisture can build up in the crankcase.
The Fix: Give it an "Italian Tune-up" (a 30-minute motorway drive) once every two weeks to burn off moisture and carbon.
The B57 (Diesel) Perspective
The B57 is a masterpiece for long-distance cruising, but short trips are its "kryptonite."
The DPF Problem: The Diesel Particulate Filter (DPF) traps soot. To clean itself, it needs to get extremely hot (Regeneration). Short trips don't provide enough heat for "Passive Regen," and "Active Regen" (where the car injects extra fuel to create heat) often gets interrupted when you arrive at your destination.
The Consequence: Interrupted regenerations lead to soot buildup, "Limp Mode," and potentially a multi-thousand-pound bill for a new DPF. Additionally, frequent interrupted regens can cause diesel to mix with your engine oil, raising the oil level and decreasing its lubricating ability.
Summary Recommendation
Choose the B58 (Petrol) if 80% of your driving is around town, school runs, or short commutes. You will pay more in fuel, but you will save thousands in potential maintenance and have a more responsive engine for those short bursts.
Choose the B57 (Diesel) only if you do at least one 30+ minute motorway run every week. If you don't give it that "breather," the emissions systems will eventually fail.
Thanks. It does seem that the petrol B58 in the 740i would be the best choice for me, but the N57 in my current 730d doesn't seem to be as problematic as I had first thought with my style of driving.
Perhaps a weekly 30-40min drive on the motorway with either petrol or diesel engine together with driving gently for the last mile or so should suffice, and with the diesel engine left to idle for 30secs/1minute if that last part of the drive hasn't been gentle.
Probably what will swing it for me is the more the spec, price & colour of those cars available at the point of me wanting to change to a newer car. A nicely loaded and priced car of either engine, with some engine sympathy applied when driving should see me ok.
Perhaps a weekly 30-40min drive on the motorway with either petrol or diesel engine together with driving gently for the last mile or so should suffice, and with the diesel engine left to idle for 30secs/1minute if that last part of the drive hasn't been gentle.
Probably what will swing it for me is the more the spec, price & colour of those cars available at the point of me wanting to change to a newer car. A nicely loaded and priced car of either engine, with some engine sympathy applied when driving should see me ok.
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