OW Impressions...

[Dr. T]

The biggest noticeable difference I've seen in using the BMW 0W-40 is how long the engine takes to warm up. It seems to now take TWICE as long to warm up compared to the Castrol TWS 10-60.

Both oils seem to crank about the same down to -20C and I drive off immediately. But, I thought a fast warm-up was the best thing for an engine. Aside from taking longer to warm-up the passenger compartment, is this increased warm-up time a bad thing for engine wear? Anyone experience this with a OW?

 

[moribundman]

The brand and/or weight oil I use has no noticeable effect on how long it takes the oil/engine to warm up. Whether I've used Syntect 5W-50 or M1 0W-40, or M1 5W-40, at normal ambient temps (55-75 degrees F), the coolant reaches operating temps after 2 miles of slow (35 mph) driving, the oil temperature reaches 190 degree F after about 6 miles of driving.

 

[Dr. T]

See Moribundman, I'm talking about at 0F or -10F (ie. winter temps), the engine warm-up time seems to be taking significantly longer. Similar to how it would if you let the engine idle vs. driving off immediately. I agree that at 60-75F, it's probably not making a difference...

 

[buster]

If anything, I would think a 0w would take longer to get a car warmed up. Oil helps cool the engine. Really not much of a difference between a 0w and 5w IMO.

 

[haley10]

This must be another issue and is coincidental.
There is no way an engine oil could make this difference.

 

[TooSlick]

Dr T,

A highly viscous, 60wt oil generates much more internal friction and heat then a 30wt or 40wt, so of course the engine warms up faster....Try filling you engine with straight, "NLGI #2" grease and it will warm up even faster...

Paradoxically, I've recently thought that a slightly heavier oil might be desirable in cold weather simply because it DOES make the engine run hotter. Provided of course it's thin enough to also allow easy cold starting ....

Take a bowl of honey or molasses and you can heat the fluid up using an electric mixer. Energy can be neither lost or gained - only transferred - and the energy required to deform any viscous liquid goes directly into heating it.

Aren't medical professionals required to take basic thermodynamics these days?

TS

 

[Dr. T]

I was just stating an observation since switching viscosities so dramatically and was asking whether or not this would account for an increase in "engine damage" due to prolonged warm-up time.

In other words....a similar argument to those that figure it's OK and recommended to use a 0W in climates such as Texas or Florida. Better flow...but, a longer warm up....which contributes to more wear?

 

[haley10]

I agree TooSlick, but I have a hard time believing this dramatic difference @ cold.

Less than adequate lubrication will definitely warm things up faster.

I think the cold weather "pumpability" is a greater issue here!

Regardless, even @ 100F ambient, I won't run anything more than a mid 40 wt. It isn't necessary. Been there, done that.

 

[jaj]

My 2003 BMW M5, with the V8 5.0 litre engine warms up faster and runs noticeably hotter with TWS10w-60 than with the factory fill 5w-30. The running difference is about 10-15 degrees celcius (the M5 has an oil temp guage instead of a fuel consumption guage). The difference is remarkable.

As for any other differences, there aren't any - consumption is less with TWS but it runs the same.

Cheers
JJ