Discussion
I’m trying to figure out if BMW under achieved on the S55 or over achieved on the B58.
I have a manual M240i, it’s been remapped at DMS Southampton, I have a dyno reading of it making 460ps (!!). I took this with a pinch of salt as there are so many tuners out there showing different figures for the b58, none of them making this much and the power delivery is so smooth, it’s not very sharp unlike my previous F82 M4 CP but I believe it now.
When I run it on 99 fuel, it feels a lot more responsive and a lot faster however I don’t need the extra power or response as I’m sort of used to it now and just cruise around now so just on normal 95 unleaded. Cost of living crisis and all that.
The other night, on a 50MPH single lane M25 that opened up with NSL resumed in the middle of the night, I found myself next to a pre LCI M4.
Side by side, the M4 had a bit of a head start against me as I didn’t respond quick enough and he couldn’t pull away from me up to about 80. It was about the same distance between us, despite this and his head start, he wasn’t pulling away at all, in fact, I was probably about to reel him in.
I think, in an ideal universe where we had the same start and I had the 99 fuel, my car would have been faster. Bear in mind my car is a manual!
I know my car is remapped, it’s not a fair comparison at all however I can’t help but wonder why BMW made an engine like the B58 that can so easily be faster/more powerful than a fully fledged bespoke M car engine.
Everybody seems to have the same opinion who talks about the B58 but as a previous M4 owner, the S55 is in a different world to the B58, the response is so instant and brutal, it really does make you feel special but when M140i/M240i’s are available for as little as 14k, with a £500 remap, they’re suddenly as fast as a full fat M car.
What we’re BMW thinking?
I have a manual M240i, it’s been remapped at DMS Southampton, I have a dyno reading of it making 460ps (!!). I took this with a pinch of salt as there are so many tuners out there showing different figures for the b58, none of them making this much and the power delivery is so smooth, it’s not very sharp unlike my previous F82 M4 CP but I believe it now.
When I run it on 99 fuel, it feels a lot more responsive and a lot faster however I don’t need the extra power or response as I’m sort of used to it now and just cruise around now so just on normal 95 unleaded. Cost of living crisis and all that.
The other night, on a 50MPH single lane M25 that opened up with NSL resumed in the middle of the night, I found myself next to a pre LCI M4.
Side by side, the M4 had a bit of a head start against me as I didn’t respond quick enough and he couldn’t pull away from me up to about 80. It was about the same distance between us, despite this and his head start, he wasn’t pulling away at all, in fact, I was probably about to reel him in.
I think, in an ideal universe where we had the same start and I had the 99 fuel, my car would have been faster. Bear in mind my car is a manual!
I know my car is remapped, it’s not a fair comparison at all however I can’t help but wonder why BMW made an engine like the B58 that can so easily be faster/more powerful than a fully fledged bespoke M car engine.
Everybody seems to have the same opinion who talks about the B58 but as a previous M4 owner, the S55 is in a different world to the B58, the response is so instant and brutal, it really does make you feel special but when M140i/M240i’s are available for as little as 14k, with a £500 remap, they’re suddenly as fast as a full fat M car.
What we’re BMW thinking?
BMW quite rightly designed the B58 to be more powerful, reliable and efficient than past engines, because as engineers they would want to eclipse previous engines on those three principles. Sometimes the bean counters get in the way, but in the case of the B58 they brought an engine to market that was an excellent power plant, and also the basis for the very powerful S58.
One of my previous cars used 5 litres to produce the same power and less torque, and did 18mpg vs 30. It’s called progress.
I’ve spent many happy miles behind this engine and revel in its smoothness and broad power band, and yes mine will be getting remapped once I’ve had the auto box and diff serviced. What were they thinking? I suspect they were looking to the future and not the past.
One of my previous cars used 5 litres to produce the same power and less torque, and did 18mpg vs 30. It’s called progress.
I’ve spent many happy miles behind this engine and revel in its smoothness and broad power band, and yes mine will be getting remapped once I’ve had the auto box and diff serviced. What were they thinking? I suspect they were looking to the future and not the past.
You can't really compare the two engines as said. A standard B58 engine should really be compared to a standard S58 really I think.
I love the S55 engine in my F82 M4 a lot, but I also love the playfulness of the LSD(M-diff) as well, and that adds a lot of character to the car as well I think. You don't get that as standard in a M235i/M240i in comparison.
I love the S55 engine in my F82 M4 a lot, but I also love the playfulness of the LSD(M-diff) as well, and that adds a lot of character to the car as well I think. You don't get that as standard in a M235i/M240i in comparison.
MikeM6 said:
Struggling to see the issue here: a modified newer engine is better than an older, standard engine.
Maybe try a modified S55? Or compare a standard B58 to an S58?
An M car has always been more than just outright power though, it's never been the absolute fastest in a straight line.
Exactly. Proper M cars that I’ve driven have a real zing to them missing from fast versions of normal models.Maybe try a modified S55? Or compare a standard B58 to an S58?
An M car has always been more than just outright power though, it's never been the absolute fastest in a straight line.
My M140i was fast in a straight line, but it was dog s
t on a Welsh B road because of the chassis set up. All of that power / potential counts for jack st if you can’t use it.Court_S said:
MikeM6 said:
Struggling to see the issue here: a modified newer engine is better than an older, standard engine.
Maybe try a modified S55? Or compare a standard B58 to an S58?
An M car has always been more than just outright power though, it's never been the absolute fastest in a straight line.
Exactly. Proper M cars that I’ve driven have a real zing to them missing from fast versions of normal models.Maybe try a modified S55? Or compare a standard B58 to an S58?
An M car has always been more than just outright power though, it's never been the absolute fastest in a straight line.
My M140i was fast in a straight line, but it was dog s
t on a Welsh B road because of the chassis set up. All of that power / potential counts for jack st if you can’t use it.Now in a G42 M240.....just as fast as my M4C but doesn't scare the s
t out of you regularly!Court_S said:
Exactly. Proper M cars that I’ve driven have a real zing to them missing from fast versions of normal models.
My M140i was fast in a straight line, but it was dog st on a Welsh B road because of the chassis set up. All of that power / potential counts for jack st if you can’t use it.
Yup, never really gelled with my M140 as similarly thought it was pretty crap in anything other than a straight line. My M140i was fast in a straight line, but it was dog s
t on a Welsh B road because of the chassis set up. All of that power / potential counts for jack st if you can’t use it.tgr said:
When was the B58 introduced for the 1, 2, 3 and 4 series? I ask because I imagine it would have been at different times.
Difficult to tell which engine is in a car from the outside
The badge on the boot gives that away. The M140i and M240i were only ever the B58 engine. The 340i and 440i is also the B58. Difficult to tell which engine is in a car from the outside
Earlier 540i and 640i are the N55.
Driver101 said:
tgr said:
When was the B58 introduced for the 1, 2, 3 and 4 series? I ask because I imagine it would have been at different times.
Difficult to tell which engine is in a car from the outside
The badge on the boot gives that away. The M140i and M240i were only ever the B58 engine. The 340i and 440i is also the B58. Difficult to tell which engine is in a car from the outside
Earlier 540i and 640i are the N55.
Stage 1 M140i/M240i/340i/440i would pull away from a standard M4 no problem. Above 130mph the M4 would begin reeling it.
Stage 1 the m4 and it will pull bus lengths on the remapped m lites.
B58 is a great engine with huge tuning capabilities and a big following. Most people go for Stage 2+ which is around 480bhp.
Stage 1 the m4 and it will pull bus lengths on the remapped m lites.
B58 is a great engine with huge tuning capabilities and a big following. Most people go for Stage 2+ which is around 480bhp.
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