Engine Oil 'Life'

It's just oil associated with combustion products that require changing.

Oil in the gearbox/diff have been "sealed for life" in the UK for some considerable time.

Good point, I'd forgotten about that- it explains the Tesla example.

If you remember 5k oil changes, you'll also remember pretty well all car makers did good business selling reconditioned engines too. The famous BMC Gold Seal units, etc. Which many garages carried in stock.

Try asking your local main agent if they stock exchange engines. ;-)

True but that doesn?t explain things directly, quite the converse.

True, if you allow for the interplay of several factors then you can explain it but not in the way you hint.

Likewise, you used to ?run engines in?, some of us still do, at least to an extent, but modern cars don?t come with the detailed instructions cars once did re running in.

I appreciate improvements in manufacturing techniques etc all play a part, plus oil technology etc. It just still seems unnatural not to change engine oil ( and filter) for 2 years and the corresponding mileage (although in our case the mileage won?t be that high, motorhomes tend not to do high mileages even the ones which are well used- we?ve done about 4.5k in 12mths over 7 trips, 3mth away).

I didn't hint at the reasons. ;-)

Running in is required due to less than ideal finishing of bearing etc surfaces. If you ever saw a freshly re-bored cylinder in those days. These days many cylinders are aluminium with a coating on that. If that coating gets damaged, repair may be uneconomic. As with everything else, machine tools can be dramatically more accurate these days.

Large engines - as found on ships etc - don't have routine oil changes. The oil is analysed and brought back to spec with the necessary additives.

Those of us of a certain age are simply conditioned into thinking oil has a certain life.

In the USA they seem to have a common belief that the oil must be changed on every trip to the bottom of the road, or at least every 3k to

5k miles!

There's no engine oil, but there are fluids - screenwash, brake, a/c gas, battery coolant. Plus tyres still wear out.

They don't need changing on an annual basis, so there's no 'annual service' which is primarily driven by the need for an engine oil change and then 101 other things added in to justify it (changing key fob batteries and greasing door hinges, and 57 varieties of 'checks' than just involve glancing at things).

Basically things just need doing as and when, not on an annual interval. But I'm not sure the costs are a lot lower as a result.

Theo

battery coolant is one of the things that is rather important.

Indeed, however it's now a 'for life' item. Possibly needs doing after >10 years, but not on a regular basis.

Theo

Unsurprising when

are owned by an oil company and recommend changing every 3k... Theo

ah, it WAS an annual service item (to replace the coolant) but as of this year they have decided it is unnecessary, apparently the coolant change was introducing dirt into the system, on new ones it invalidates the warranty to open up the cooling system as an owner.

But not 50 years ago, when I started maintaining cars and bikes. The oil technology has improved, but also the manufacturing technology. Plateau honing is the reason we hardly ever hear of rebores these days (ok motorways help). I suspect that in gearboxes, surface finishes are much better and gears don't shed "bits" when first run, like they used to.

Good point. Since 1960 the maintenance procedures for power station steam turbines and other large rotating plant discuss "spiking" with additives if analysis shows a fall in properties (typically anti corrosion or anti foam). But I can't recall a single instance. I was involved in an oil change once because of a biological infection in the oil.

You do mean primary coolant, don't you.

Before that .... in the 70's my dad told me that his dad ...

1950's Ford Pop side valve needed an annual de-coke. It was cheaper to fit a new short engine £12 in the crate. In and out the workshop in a day.

Late 60's dad had a Triumph 2000, snapped the crank while running in.

By the 70's Ford were making the OHC Pinto, fitted in Cortina and Capri. Cam and rockers needed replacing at 50K miles as the oil jets in the spray bar blocked up. It was so common that motor factors had the full kit of parts hanging on the wall behind the counter in a blister pack.

Go back to the 30's, inline 4 cylinder cranks lacked balance webs. Due to crank flex, they all could suddenly and inexplicably wear out the mains and this is why so many people held some notion that high revs destroys engines and that slow revving long stoke engines are "better". (A polish tractor maker is still making "bent stick" cranks and yes they break, most people with any sense buy the version with a CAT engine.)

The 1970's OHC Datsun L series engine in the Bluebird that did 100K miles with 'just servicing' was a revelation and made everyone else up their game. It's origin was a Mercedes inline 6 but "improved", to the point that the licence fee was no longer payable. The Merc was a high cost luxury car in the UK and reliability was expected with the price while the Datsun was competitive with Fords. So don't pray to God for a Mercedes, pray for something better in a chassis that doesn't rot...

Did you not read the bit where they're moving away from 3k recommendations?

The oil company in question invests a lot of money into extending the life of oils, too...

I'd say the American model is very much down to their hugely inefficient engines which I'd quess contaminate oils very quickly as they don't burn fuel anywhere near as efficiently as the rest of the world.

well as the battery is the primary (only) power source in a Tesla, then you could call battery coolant the primary coolant, but people would not understand.

I was told the 'motor' (I suspect battery) coolant was the same kind as used for the normal (Combustion) engine in our Outlander. Certainly when you check it, it appears the same - nether it or the engine coolant have needed topping up yet. (The two systems aren't shared.)

Yup. And often when they don't keep a car long enough to know for sure it has made it last longer.