Which Oil Weight for the M60?

[Jehu]

When I bring the 540 in for the Timing Chain Cover gasket,Power Steering hose job this Tuesday I'd like to bring Royal Purple I've been using for a long time for them to refill. I have been using 10w30. Is this BMW Indy likely to reccomend 5w-30 ? I think I recall him suggesting 5w-30 in the Summer but i guess i haven't properly understood the function of motor oil and am stuck in the old mindset that thicker oil offers better protection. Should I bring 5w30 and use that thru the hot Summer months here in the Northeast USA or stay with the 10w30

[Ross]

As I understand it the second # indicates viscosity at 100c, so no difference other than flow at low temps.

[Zeuk in Oz]

I use Mobil 1 0W-40 in all of my cars, changing every 7-8,000 km (5,000 miles).

[bad_manners_god]

I use Mobil 1 0W-40 in all of my cars, changing every 7-8,000 km (5,000 miles).

That's some of the best oil's out there. Here in Canada I usually go with a 5W-40 all year round.

[Tiger]

5W helps with fuel efficiency when cold... 0W is even thinner

Same is said for 30 weight... thinner means better fuel efficiency than 40.

Some modern low emission engines even go thinner... 0W20... yes... 20W.

Synthetic oil are incredible nowdays.. that offers superior protection regardless of what grade oil you want to use... In today's gas price. I am tempted to even try the 0W20 to see what fuel mileage I can get.

[Paul in NZ]

if the 5w 30 is the llo1 spec i beleive it has number s more like 5 w 40.Its likely thats what BMW thmemselves would use,maybe even their 10 w 60

[bubba966]

I use Amsoil Signature Series 0w30 in my M60. Nice stuff but not cheap at nearly $10/quart.

With good synthetics you don't need heavy oils. And in fact heavy oils don't circulate though the engine as well and don't get cooled down as well. Higher oil pressures = hotter oil temps. Ideal oil pressure is around 10psi per 1000RPMs. At that pressure the oil is still protecting things, and is circulating well which provides maximum heat disapation.

Lighter oil also allows the engine to run a little freer which in turn provides a little better fuel economy.

[Paul in NZ]

I use Amsoil Signature Series 0w30 in my M60. Nice stuff but not cheap at nearly $10/quart.

With good synthetics you don't need heavy oils. And in fact heavy oils don't circulate though the engine as well and don't get cooled down as well. Higher oil pressures = hotter oil temps. Ideal oil pressure is around 10psi per 1000RPMs. At that pressure the oil is still protecting things, and is circulating well which provides maximum heat disapation.

Lighter oil also allows the engine to run a little freer which in turn provides a little better fuel economy.

and they provide better cold start protection