Age old Question/Argument

[packratbimmer]

I think an important fact or two are important here

1) Oil technology has changed drastically since the mid eighties

2) Many modern 5w 30 oils have very little zddp (modern engines don't need it)

3) Most E30 M20 cars have already experienced considerable valve train wear over the last 25-30 years

* Using heavier oil in a worn engine masks problems

[digger]

the best way too determine a suitable viscosity is install a temp and pressure sensor.

but there are more important things than just viscosity that affect the amount of protection an oil provides, its only 1 aspect of the decision on which oil to use

[Northern]

I see a lot of people in the US running 5w30 in the winter? I'm sure that if 10w40 worked for me(and the rest of all e30s) for years, that a thousand miles further south it'll work just as well...

[jeffnhiscars]

I think an important fact or two are important here

1) Oil technology has changed drastically since the mid eighties

2) Many modern 5w 30 oils have very little zddp (modern engines don't need it)

3) Most E30 M20 cars have already experienced considerable valve train wear over the last 25-30 years

* Using heavier oil in a worn engine masks problems

More like it compensates for wear whereas a thinner oil is far more likely to grenade a worn engine...and yes this thread still offends me :p

[packratbimmer]

I find it offensive that 20W 50 won't flow to my cam when it is 20 degrees below zero, but that's just me.

[digger]

yeah the oil pressure would be maxxed out at 70psi at idle until it warms alot....and you know what that means, flow is compromised at the far end of the system.

i wouldn't use a 20W-50 if it got below 15C and i was doing lots of cold starts twice daily like a DD car often would

[dnguyen1963]

15C is 59F and that's why many of us Northerners use 15W40 oil.

[digger]

not many are worse than 20W-50 when cold but if you compare a 10W-40 to 15W-40 is seems like 10W-40 is much better suited to a northern winter

http://www.viscopedia.com/viscosity-tables/substances/engine-oil/

[dnguyen1963]

Yes, 10W40 is slightly better than 15W40 in the winter. I just have been using 15w40 diesel oil for a long time. I can get a gallon of Rotella 15W40 for $12 vs. $22 for Castro or similar 10W40.

[packratbimmer]

If I had a driveway, I would use a block warmer.

[dnguyen1963]

If I had a driveway, I would use a block warmer.

It would be fine if you have an electrical outlet. Your work place and any other place you need to go to during the day might not have one.

[packratbimmer]

It generally warms up during the day on Earth

[dnguyen1963]

It generally warms up during the day on Earth

yeah...going up from -15F to 5F is not going to help much in the dead of winter. In the past few years living in Madison, the average temp was around 5F during the month of January and February.

[packratbimmer]

A block warmer would help to establish a base line temperature for morning starts during negative spikes. With that baseline a firm choice could be made about the viscosity given the severity of the winter. I do not want to run 5w 20 all winter for the 10 days that the extremes hit. I think Madison is colder than coastal Maine on average BTW.

Not sure if you read my previous post with the pic - I learned a lot when I shot a temp of my block at noon that day. It was in the high teens ambient, but my block was still -12F.

[dnguyen1963]

A block warmer would help to establish a base line temperature for morning starts during negative spikes. With that baseline a firm choice could be made about the viscosity given the severity of the winter. I do not want to run 5w 20 all winter for the 10 days that the extremes hit. I think Madison is colder than coastal Maine on average BTW.

Not sure if you read my previous post with the pic - I learned a lot when I shot a temp of my block at noon that day. It was in the high teens ambient, but my block was still -12F.

Yes, I saw your post. My point is a block warmer is not going to help when you are at work if you have no electrical outlet. You can start your car in the morning at home, but then you'll be stranded in the evening when the temp dropped way down. In all honesty, my E30 was parked most of January when I lived in Madison.