BMW recently serviced- questions

Smart cars don't have them; aftermarket converted ones are available!

Chris

and of course cars with oil coolers leave a good bit in the system to contaminate the fresh oil. IMO regular changing with good oil is the real answer then the junk doesn't glue itself to the inside of the engine.

Yes.

I don't know any that fit that category.

However a road car isn't going to spend most of its time doing hard work or being WOT.

& if you on;y do 5 miles a day your BMW will be demanding an oil change sooner.

the OP BMW has only averaged 20 miles day, so probably a lot of the time it does only do a very few miles in a day, as to when the computer demands an oil change ?. The lorries I know of usually run for most of the working day, some are running almost 24 hours as they have shift drivers , the oil would never have have time to cool down to ambient, also of course lorry engine 2,250 rpm (about?) flat out, BMW 7,000 rpm.

& hence setting an oil change limit based solely on mileage is pointless.

The BMW system varies the change depending on lots of inputs, quite how short an interval or how long I don't know, but it does vary for sure.

The Original Smart is the only one i can think off. The new ones all have a plug, and the old ones can be retrofitted...

Tim..

Probably not with a 0W30 BMW Longlife 04 - it's properly expensive.

..for a petrol beemer. For my diesel one, it tells me to change up at

1500rpm (even under noticeable acceleration or even less rpm if I'm not) and I could certainly spend all my time below 1500rpm and not hold anyone up either. For oil life expectancy, I wonder if average revs is more significant than infrequent peak revs.

I'm guessing, but lorries probably use all their rev range more of the time than cars. When I worked in a lorry depot, they all tended to get started up from cold and red-lined for a good few minutes before moving off. Gently treated? Never.

Lorries tend to run bigger filters and gallons of oil and are limited to around 56 MPH

And? The engine is working at a higher load than a car one is. Even when travelling down a motorway, in the UK it is possible for large stretches to be at 50% or more at full load. Take "Windy Hill" on the M62 westbound. All the way up apart from about 1/2 mile, a lorries engine will be working flat out whereas a cars isn't, even on the steepest part.

The engine is also geared accordingly and usally has a greater capacity plus the power and torque of the engine are set differently

Most lorries have greater pulling power in the lower rev

Windy hill is just a very small section of motorway

Lorry engines are far better engineered for pulling loads

Why do you think most lorries oil changes are double even tripple those of cars

Irrelevent.

All of which still doesn't alter the fact that they spend a fair bit of time with the foot hard to the floor, wide open throttle.

However having driven the full entire UK motorway network many many times over, there are very few flat sections.

Because its better quality and they employ centrifugal oil cleaners.

Not if your driving the lorry

What relevance is that , just because the foots on the floor doesnt mean that the engine is running at full power far from it on modern lorries where the throttle has no direct link to the engine and everything is controlled by computer modules , once you reach the limits programmed into the unit the power is backed right off , just enough to keep the vehicle at 56 mph on most vehicles , usally running at the most economical fuel setting

Yes some up hill other down

Hmmm....Are sump plugs not sometimes magnetic and pick up small amounts of swarf that are swilling around the engine ?

As soon as you're doing less than 56 it'll be flat out though.

Sometimes, some cars have a magnet on the sump pan or the oil filter. But if you've got an alloy block & head there's unlikely to be much swilling around to be caught by it.