Auto start/stop is a brutal process. Basically it’s similar to "cold starting’ your engine with 0 oil pressure every time you stop, since the oil pump runs off the crank (though all the fluids are up to temp already if you’ve been driving which does help quite a bit).
~rant time~
Cold starts are the hardest on engines since usually all the fluids aren’t warmed up making them more viscous, the engine has not experienced any thermal expansion to the proper spec, and any oil has drained to the pan from sitting, leaving minimal amounts in the head/pistons bearings etc.
This is why you always wait a ~30secs-1min before driving, and up to 5-10 mins before driving hard on a car, as it needs time to disperse oil, heat up components and oil, and get things to spec. It’s also why engine builders when finishing a build will pull the fuel pump fuse and crank the engine a couple times to build oil pressure before starting a new build to make sure everything is coated for first starts.
~rant over lmao~
To counter auto start/stop issues, BMW coated the rod bearings with an IROX polymer that is more durable and decreases friction during this process with low oil pressure.
I highly recommend you watch the Papadakis B58 teardown video. It is very interesting and goes into high detail + shows you everything about the motor from an experienced builder.
Also I’m not saying the B58 is the perfect engine. It has it’s goods, bads, and uglys. From everything I have learned about it to what I have seen and what others have said, it looks really stout to me, even though I don’t have a lot of hands on experience myself.
By the way, what did they upgrade in the bearings for the start stop and why ?
Auto start/stop is a brutal process. Basically it’s similar to "cold starting’ your engine with 0 oil pressure every time you stop, since the oil pump runs off the crank (though all the fluids are up to temp already if you’ve been driving which does help quite a bit).
~rant time~
Cold starts are the hardest on engines since usually all the fluids aren’t warmed up making them more viscous, the engine has not experienced any thermal expansion to the proper spec, and any oil has drained to the pan from sitting, leaving minimal amounts in the head/pistons bearings etc.
This is why you always wait a ~30secs-1min before driving, and up to 5-10 mins before driving hard on a car, as it needs time to disperse oil, heat up components and oil, and get things to spec. It’s also why engine builders when finishing a build will pull the fuel pump fuse and crank the engine a couple times to build oil pressure before starting a new build to make sure everything is coated for first starts.
~rant over lmao~
To counter auto start/stop issues, BMW coated the rod bearings with an IROX polymer that is more durable and decreases friction during this process with low oil pressure.
I highly recommend you watch the Papadakis B58 teardown video. It is very interesting and goes into high detail + shows you everything about the motor from an experienced builder.
Also I’m not saying the B58 is the perfect engine. It has it’s goods, bads, and uglys. From everything I have learned about it to what I have seen and what others have said, it looks really stout to me, even though I don’t have a lot of hands on experience myself.