How Often to change the Oil

Heh. Though that may actually not be as daft as it sounds. It probably wouldn't be too difficult to program a system to make certain assumptions about the condition of the oil just based on facts and figures i.e. throttle positions with relation to oil temperature (i.e. has it been thrashed from cold?), no of short journeys from cold, average journey length, etc etc. Could potentially be more reliable than being put at the mercy of a sensor.

That would be the case on a FWD with small wheels. But a Minor had neither. And things like grip didn't matter much in those days. ;-)

Six Cylinder diesels from VW, used in Volvo cars and LT vans? You sure you don't mean 5-cylinders? And I've never heard of them snapping camshafts.

It'd be helpful if they published the actual pressures in the handbook! In the one for my Citroen Relay van, it mentions how important it is to the run the tyres at the correct recommended pressures several times, but not once does it mention exactly what those recommended pressures are.

Yeah, and when the garage ask, it'll be like "oh, that - yeah, that's been on for ages - still seems to run ok - engine's a bit noisier though".

Heh - one main thing that put me off leasing vans is the term in the contract that said that the "owner" (i.e. the leasing company) may not be funding the vehicle with their own money, but with the funds of the "head lessor", who then rents it to the "owner", and that if the "head lessor" decided to put up their rental rates to the "owner", then the "owner" would be entitled to increase the monthly lease cost to maintain their rate of return on investment. Now I'm no financial expert, but to me that's as bent as f*ck.

BMW and Mercedes, if not the others also, do indeed do this in addition to measuring the condition of the oil as a back-up.

Huw

No I mean six cylinders and you may be too young ;-)

Huw

In my student days, around '76, I worked at a place that ran a small fleet of the damned things and they were fairly new but hopelessly outdated by then. No grip around corners. Hopeless brakes. Some gearboxes that jumped out of third and needed a kee to hold them in gear. Pedals that exitted through holes in the floor. Yuk! By this time the Maxi, Marina and Allegro were well established and highlighted starkly the minor as being passed its sell-by date.

Hooray for modern transport!

Huw

Yet another discovery that a great idea I've come up with has already been thought of! D'oh!

Oh they're quite good at it :-(

And besides, since when has Mitsu built EvoVIII engines in Europe?

Huw

Ah! how do *you* know it isn't?

Service intervals are set by the manufacturer for only one reason - to make the car appear cheaper to service when a customer buys it. It's more to do with fleet buyers than anything, if you can show that a car has less services during a normal contract period, then you're more likely to sell to them.

As long as a car can make it through that period, then that's all that matters.

I've seen fleet run cars expire at 120k, yet privately owned examples with reduced intervals of servicing have made double that.

That was a design fault for sure, but I never mentioned the OHC engine, it's the OHV engine I'm talking about. Worn out pistons and bores by

I've seen CVH engines make 240k with 6000 mile servicing.

Again, are you sure about that? I've been observing the nature of engine wear over 25 years across different brands.

I have compared, first hand, the condition of identical engines that have been subject to both 6000 miles and 10000 mile intervals (a change in service intervals set by the manufacturer at a given date). The difference is astounding when you compare the condition of those engines after, say, 50k.

At that time we were using Castrol TXT - supposedly tested for 18000 miles of use.

No it's not, it's down to bad choice of specification to meet cost criteria.

Not on all cars. I can honestly say that I've not seen a premature belt failure on a Honda.

A well designed engine.

Yes, it was used in the LT vans and Volvo 700 and 900 series cars. It was a s**te lump too.

Have you looked inside the door jam?

I'm talking about '52. ;-) When similar Fords had side valve engines and rod brakes. And 6 volt electrics. No heater either.

We were somewhere around Barstow, on the edge of the desert, when the drugs began to take hold. I remember "Dave Plowman (News)" saying something like:

I think Andy probably meant 3000 miles. I can think of one right away - the Renault 1000, 1100 engines had intervals of 3K. Not surprising really; some models didn't actually have an oil filter at all.

No, I did mean 300 miles. I read it in a classic car book, but at this time I can't remember what car it was.

Yup, since discovered them in there! But it's a bit disconcerting that they're not printed on any of the entire ranges of pages listed next to "tyre pressures" in the index of the handbook.....

In message , "Dave Plowman (News)" writes

Well I'm sure I've just read a post from Andy Hewitt (who I believe has been in the car servicing business all his life) saying that he's seen privately owned, over serviced cars last twice as long as the same car owned by a fleet operator and serviced at the recommended interval.

I've also read a report recently that Fords own 5W-30 oil is marginal on protection as it approaches its 12.5k mile drain interval. Now you might say "use a better quality oil" but I prefer to change it a 6k miles.

There is always pressure to reduce costs but reduced costs cannot be at the expense of long term reliability otherwise sales will suffer. The technology used to achieve reduced lifetime cost actually increases manufacturing costs. The customer looks at liftime cost among other things when buying a car, otherwise only the cheapest purchase price would dominate their decision making.

It's

Fleets look at lifetime costs. You assume that fleets change cars at relitively low mileage when in actuality many business fleets run to minimise costs which means keeping their vehicles to the maximum economic life. The longer they last with the minimum of cost, which includes servicing AND repair the better. Todays cars are generally kept for far longer than thirty or forty years ago. I know fleets that, back then, changed every forty thousand but which today expect a minimum of 120,000 miles from their cars and vans, and some are kept almost indeffinately.

I had several of those in Ford Escort and Cortina's and the early ones didn't last much more than 80,000 miles but a 1600 CortinaMk3 I bought used from an antique dealer was mercilessly thrashed by me for another 50,000 before I smashed into a Christmas tree and it ran like a watch. It was serviced at the then official 6000 miles. The early escorts were serviced at

Absolutely. Stress fracture of camshaft unrelated to servicing.

I cannot agree. Engines last longer than ever before and it is very unusual for an engine serviced as recommended to wear out before something else fails or it dies of old age. They fail for all kinds or reasons like stress or ancilliary failure but not generally lubricant related.

In what? The oil may be good for much longer but if the engine contaminates the oil to saturation or dumps massive condensation into it before 18000 then that's no use to man nor beast. Not just the oil life is used to determine service intervals.

It seems you will argue that black is white. What you say there is bad design!

Nor a Land Cruiser because they are better designed which rather proves what I said above. They are still a cheap design alternative though but of course all such mechanisms, even gear trains, are ultimately prone to failure.

Thank you. Yes.

Huw