Oil changes... What are your thoughts?

[joshwa]

Hi,

There still seems to be plenty of different theories abounding about oil changes. I generally tend to stick to annual services for oil changes (I do maybe 10K a year max).

BUT according to this article this: 12,000 miles is FAR too long:
https://jalopnik.com/i-found-out-wha...oil-1762314484

In the UK, a lot of cars are on "Long life" oil services... 17K seems common looking at some cars service history.

Someone enlighten me...

How does a "Modern" 2008+ car on "Longlife" oil compare to a, 2002 car on fully-synthetic (5/30), or a 1989 1l petrol on semi-sythetic?

Josh

[Butcher]

Americans have this crazy idea that any car which doesn't have its oil changed every five minutes is a ticking time bomb. And yet a lot of their changes are crap as they just suck the oil out the top (leaving all the crap in the sump) and put in new oil. Jalopnik using a single knackered car as their main data point is dubious to say the least as well.

I'd say 10k as a decent change interval, the longer ones start to get a bit iffy as your oil filter will only hold so much crap. This assumes a decently specced synthetic or semi-synth oil.

As for the modern vs old car thing - a lot of it depends on the oil. Modern oils will go longer between changes without breaking down, so the extended intervals are more a function of modern oils than modern engines.

[peterb]

I follow the recommended service intervals. A lot depends (or used to) on how the car is driven. Short stop start journeys tend to dirty the oil more than long runs. Modern synthetic oils tend to break down less than mineral based oils (but cost a lot more ! )

[Butcher]

I follow the recommended service intervals. A lot depends (or used to) on how the car is driven. Short stop start journeys tend to dirty the oil more than long runs. Modern synthetic oils tend to break down less than mineral based oils (but cost a lot more ! )

Not that much in it these days. A mineral oil costs around £4-5/litre. You can buy fully synth 5W40 for that now. Thinner grades cost more though, and as modern cars tend to move to thinner oil, the cost has gone up. Mine uses 0W20 which is at least £10/litre.

[Jonj1611]

Change my oil and filter yearly regardless of mileage.

[CAT-THE-FIFTH]

Just check the oil - if you notice its starting to change colour,change it even if its before the recommended time or mileage interval.

[Zak33]

Oil contains lots of stuff. Cool stuff.. like detergents and additives.. and bad stuff, like Suphur, Ash, Potassium (SAPs)

the chains of molecules need to stay together for the life of the oil. The sheering properties of an engine, (pulling the molecules apart for want of a better word), under both super hot temps, ice cold temperatures, while potentially having small amount sof combustion gases mixed into them, makes engine oil life HELL ON EARTH.

Imagine this - 1 engine with slight wear on one set of piston rings, meaning that a tiny tiny amount of exhaust gas is squished through the rings down into the sump on every ignition/expansion cycle of the engine

1 engine doesnt have that, but runs in freezing temperatures, gets super hot.. and every day splashes through puddles of ice water, cooling the sump over and over.

I cannot tell you what this does to the oil, but I am sure it's DIFFERENT for both. And not pretty.

Then another engine that revs to 7000rpm every day.. and another that ticks over in traffic ... but undergoes lots of stop start because of the Stop/Start system. When an egine stops turning, the oil pressure in the bearings that support the crank shaft is squished out... over and over. Same for the cam shafts.

and then a fourth engine that never gets warm. It turns on, drives 3 miles switches off.. and 7 hours later turns on drives three miles and turns off.

Cheap oil, ala American cars of old, where you could get the oil changed every 3750 miles or allegendly lose your warranty... had cheap oil. badly refined bulk rubbish. But it came free with a steak meal (yes.. American drive through oil service and dinner)

Mobil, a LOOOONG time ago cameout with Mobil1 and I ran it in my rally cars. It came out looking/feeling like brand new ...unlike the old 10w40 that was black after 3 events. Mobile tried and failed to hold the legal rights for "sysnthetic". It was never gonna stick.
But they did a great thing in my opinion, they got top grade oil to the masses. Bloody expenvie but very good.

Look up what spec you engine needs and stick to it. Dn't run fully synthetic 0w30 in a classic. Don't run 10w40 is a modern BMW.

ALWAYS change the filter with the oil
ALWAYS buy A QUALITY FILTER - the hydraulic pressure bearing into the centre of an oil filter can crush a weak filter core.

And dip it often

[ik9000]

I'm new to all this lark, but the one thing they impressed on me at the purchase was that i must must must use the right kind of oil for the car, or bad stuff happens. A certain P-blah-blah-blah. It's in the manual, I'll read it in a few months when I prepare for the MOT (last check the level was ok). "Normal oil" whatever that is, is not ok. It must be this synthetic P stuff.

[CAT-THE-FIFTH]

I know my mates Skoda with a diesel engine needs very special stuff according to him,which is rarely on offer.

[ik9000]

I know my mates Skoda with a diesel engine needs very special stuff according to him,which is rarely on offer.

that is exactly what I'm talking about. You can add me to that list.

[DanceswithUnix]

Get a good mechanic, do what they say

I tend to consume cars rather than sell them on, and have had cars from reasonably low mileage where I run them on fully synthetic oil but as they get older you switch to something like magnatec because a thin oil burns off too fast. So no general rule really.

3000 miles for an oil change though? Get better oil, that is nuts.

Limit for how long you should wait depends on how the car is used. My low mileage Alfa will probably have done 8K miles when the yearly service comes up and the service indicator probably wouldn't come up for another 10K as I hardly get to bounce the rev counter off the limiter, but at MOT time I will get a service done with oil change anyway as fluids can be a bit manky after a year. I think the official schedule for my car is 18K miles or 18 months, but yearly isn't exactly a chore.

OTOH, if you have been on a track day then it is probably worth an oil change regardless of distance covered.

I used to work with someone who back in the 90's bought a brand new BMW 3 series and with his very long commute he drive it for three years just topping it up. I think it was his first MOT when he figured he should have the car serviced and the engine was running but in pretty bad shape, but thanks to his very long commute he had done something like 150K miles by then. That's another single data point, but shows that the world doesn't end at 12K miles.

[CAT-THE-FIFTH]

that is exactly what I'm talking about. You can add me to that list.

OTH,if it is the same engine he has,its very reliable from what I gather.

[DanceswithUnix]

I know my mates Skoda with a diesel engine needs very special stuff according to him,which is rarely on offer.

With a gazillion VW diesels on the road I distinctly doubt it. My wife's old Alfa with a Busso V6 is rather rare and hard to feed, yet there was still one 5l bottle of the correct grade of Mobil 1 synthetic at the local Halfords so even for that I didn't have to resort to the internet. I still see that on offer occasionally.

OTOH I did laugh a while back at the local Sainsbury's where they had bottles of oil labelled "For Ford diesels", "For VW diesels" etc which I suspect all came from the same nozzle at the refinery

[CAT-THE-FIFTH]

With a gazillion VW diesels on the road I distinctly doubt it. My wife's old Alfa with a Busso V6 is rather rare and hard to feed, yet there was still one 5l bottle of the correct grade of Mobil 1 synthetic at the local Halfords so even for that I didn't have to resort to the internet. I still see that on offer occasionally.

OTOH I did laugh a while back at the local Sainsbury's where they had bottles of oil labelled "For Ford diesels", "For VW diesels" etc which I suspect all came from the same nozzle at the refinery

I dunno,from what I gather its never on offer and he is a bargain hunter like me! Its a specific weird grade,and I am sure he would be quite happy to use cheaper stuff!!

[peterb]

Volvo marine used to insist on their brand of oil in their marine diesel engines or they would void the warranty.

It was actually a shell marine oil, but had specific trace additives so Volvo could see if the 'correct' (ie Volvo) oil had been used in the event of a warranty claim.

Naturally it cost considerably more than the Shell equivalent.

[Zak33]

Volvo marine used to insist on their brand of oil in their marine diesel engines or they would void the warranty.

It was actually a shell marine oil, but had specific trace additives so Volvo could see if the 'correct' (ie Volvo) oil had been used in the event of a warranty claim.

Naturally it cost considerably more than the Shell equivalent.

and so long as the full disclosure occurs at point of buying it, ... fair enough.

Its like buying a Honda Jazz thinknig it's the smallest and cheapest car in their range back in the day, only to find it had 8 spark plugs and they needed changing every two years. So long as you knew when you paid for the car, happy days.

Oil refining companies are very interesting places with very clever people.. not just marketing bods.

I'm not one to pimp ..but these lads/lasses know their stuff


check the diff tech sheets

https://www.morrislubricants.co.uk/d...BEngine%2BOils

He's an example of a 5W/40

Performance Levels
API SN/ CF
ACEA A3 / B4
Renault 0700 and 0710
Fiat 9.55535
-
G1 / H2 / H3 / M2 / N2
MB 229.3
Opel GM-LL-B-025 (Diesel)
VW Standard 502.00/505.00
Porsche A40

Physical Characteristics
Viscosity @ 100C, cSt.14.79
Viscosity @ 40C, cSt. 92.35
Viscosity Index 173
Density at 15.6C 0.860
TBN, mg/KOH/g 11.2
Flash Point (Closed) C 204
Pour Point, C -33

the next closest, a 5W/30 is v different. They have to blend all those.