This is a follow up to another thread i made a while back asking people about their experience running 0/5W20 in old engines.
I've been leaning towards thick oil since i know what oil is and only cared about xW40 ones. Probably because i'm european and have been told about the inevitable disasters that will happen if 5W30 is used in an engine because it's like water. I am more and more interested in experimenting with thinner oils in my application as i am learning about the possible benefits they can offer as well as how bearing clearances and oil pressure work. I've established that running a synthetic ressource conserving 5W30 is in my engine is in fact more than safe.
Here are the values found in the service manual for my engine:
Main bearing clearance: between .025 and .045mm = between .00098 and .00177 in inch.
Rod bearing clearance: between .030 and .050mm = between .00118 and .00197 in inch.
Mininum oil pressure at hot idle: .3 bar = 4.35 psi.
Minimum oil pressure at 3,000 rpm : 3 bar = 43.51 psi.
I've heard about the 10 psi per 1,000 rpm rule and from experience these engines run much higher pressure than that even if MB says 4.35 is acceptable at hot idle (that seems extremely low). The typical pressure is more like 1.5 bar (14.5 psi) at hot idle and the gauge usually pegs at 3 bar (43.5 psi) between 1,500 and 2,000 rpm when hot on all the M1xx gas and OM6xx diesel engines.
I've never been able to get my oil temp higher than 95c (203f) after an italian tune up but that was in winter and it seems to follow coolant temps most of the time, around 80c. It is safe to say that i will rarely encounter extreme oil temps. Most of my driving is very relaxed, mostly 2,500 rpm highway cruising and hypermiling.
I just came accross this chart on the Driven Oil catalog, i've circled what corresponds to my engine's bearing clearances and oil temps.
Driven XP10 = 0W10
Driven XP2 = 0W20
Here's the chart on my (somewhat outdated?) owner's manual: The requirement was MB229.1 or API SH if not available.
Conclusion: It seems evident than running a low HTHS 5W30 (A5/B5 or ILSAC) should be harmless year round in my application, theoretically even a 20 but that raises others questions and a few concerns about other things likes piston rings etc. Is my logic skewed? please chime in!
I've been leaning towards thick oil since i know what oil is and only cared about xW40 ones. Probably because i'm european and have been told about the inevitable disasters that will happen if 5W30 is used in an engine because it's like water. I am more and more interested in experimenting with thinner oils in my application as i am learning about the possible benefits they can offer as well as how bearing clearances and oil pressure work. I've established that running a synthetic ressource conserving 5W30 is in my engine is in fact more than safe.
Here are the values found in the service manual for my engine:
Main bearing clearance: between .025 and .045mm = between .00098 and .00177 in inch.
Rod bearing clearance: between .030 and .050mm = between .00118 and .00197 in inch.
Mininum oil pressure at hot idle: .3 bar = 4.35 psi.
Minimum oil pressure at 3,000 rpm : 3 bar = 43.51 psi.
I've heard about the 10 psi per 1,000 rpm rule and from experience these engines run much higher pressure than that even if MB says 4.35 is acceptable at hot idle (that seems extremely low). The typical pressure is more like 1.5 bar (14.5 psi) at hot idle and the gauge usually pegs at 3 bar (43.5 psi) between 1,500 and 2,000 rpm when hot on all the M1xx gas and OM6xx diesel engines.
I've never been able to get my oil temp higher than 95c (203f) after an italian tune up but that was in winter and it seems to follow coolant temps most of the time, around 80c. It is safe to say that i will rarely encounter extreme oil temps. Most of my driving is very relaxed, mostly 2,500 rpm highway cruising and hypermiling.
I just came accross this chart on the Driven Oil catalog, i've circled what corresponds to my engine's bearing clearances and oil temps.
Driven XP10 = 0W10
Driven XP2 = 0W20
Here's the chart on my (somewhat outdated?) owner's manual: The requirement was MB229.1 or API SH if not available.
Conclusion: It seems evident than running a low HTHS 5W30 (A5/B5 or ILSAC) should be harmless year round in my application, theoretically even a 20 but that raises others questions and a few concerns about other things likes piston rings etc. Is my logic skewed? please chime in!