My previous B6 Audi A4 had 100,000 miles on the clock when I sold it. It was on the variable servicing regime and went up to 24k between oil changes. Never missed a beat - not a single engine mechanican problem whatsoever.
My previous 2000 (W) Golf 1.9 GT TDi (115PS) was the same - I sold at 100,000 miles - standard time & distance regime, oil changed every 15k - not a single engine mechanical problem whatsoever.
I would *never* bother changing more frequently than the manufacturer intervals (I've got better things to do with my time & money!). I never keep my cars over 100k miles, as too many other things start wearing out and costing money (clutch, exhausts, starters, alternators, steering racks, etc) so why should I bother investing time and effort into trying to make the engine last longer? So what if the engine goes pop at 150k wheras more frequent oil changes would have made it last to 170k? It's the new owners problem not mine! :-)
And before anyone starts bleating on about the moral implications of that, just remember that every lease company on the planet adopts the same approach.
A friend of mine had a Honda Civic from new. In the 8 years he owned it it never once had the oil changed! (in fact he only ever topped it up when the oil pressure light came on!). Apart from sounding very tappety, it still ran fine. (though I must admit I personally wouldn't have bought it from him!)
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Interestingly, was down the pub last night and happened to be talking to a car rental company proprietor who has ran a fleet of a cars and light vans for many years - so basically someone who has a lot of experience on how to get the maximum life out of a car.. He typically runs his cars up to 100,000 miles and only ever does oil changes every 15,000 miles* and has never had any engine wear-related problems as a result of that.
He laughed his socks off when I said there's people out there that still change their oil every 6k nowadays.
*=(he ignores manufacturer stated service intervals for oil & filter changes as warranties aren't valid for cars used as rental cars anyway)
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it probably dosen't take very long to reach 100,000mls with a hire car maybe what 3yrs?, however for somebody who does 8,000mls a year stop start journeys there will be condensation building up so lower intervills make sense? when i used to repair/rebuild forklift trucks the company i worked for changed the oil every 4,000mls diesel or lpg engines and those were lasting 250,000mls before any major work was needed!
end of the day it's up to yourself i don't think £15.00 every 6 months will kill my pocket and would feel much happier knowing fresh oil is there, but thats my opinion!!!
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Oils have vastly improved since 60s
www.imakenews.com/lng/e_article000346479.cfm?x=b11...w
tinyurl.com/yzk4x9 Link to a pdf document on www.bp.com/ shortened as was screwing up the page width of the site - DD
Mobil 1M mile test
www.mr2.com/ARTICLE/Mobil1.html
Real life testing
neptune.spacebears.com/cars/stories/mobil1.html
Most US Synthetic oils are Group III mineral oils and not PAO, quality viscosity improvers are difficult to source in US, and due to CAFE low energy conserving oils are often used. Testing has shown even Mobil is using Group III in US despite their objection to Castol calling Group III synthetic.
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Thanks mgbv8. This makes very interesting reading - the 'Real life testing' article particularly.
As I've said earlier, I tend to change my oil & filters twice yearly at about 5-6k miles. I use full synth in the Passat 1.8 turbo and semi-synth in the Zafira 2.0 DTi and genuine filters. The oil tends to be Comma or Halfords stuff. I've adhered to this sort of schedule for the last 20 years on all my cars, mostly out of habit and the 'feel -good' factor I guess. Perhaps I should reconsider as I can't imagine that I'll ever run a car past 150k miles. Mind you, the Castrol long life oil is horrendously expensive when I've seen it in VW dealers - £50+ for 5 litres.
Your comments about oil quality in the US might explain the vast differences in manufacturer servicing recommendations across the Atlantic.
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You should be able to double your intervals (i.e. 12k) using the same oils (i.e. not OEM long life stuff) unless you use in extreme environment.
Neither of those engines are particularly hi-tech and need anything special....
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Interestingly, was down the pub last night and happened to be talking to a car rental company proprietor who has ran a fleet of a cars and light vans for many years - so basically someone who has a lot of experience on how to get the maximum life out of a car.. He typically runs his cars up to 100,000 miles
So he runs a car rental company with cars doing up to 100K !! I wouldn't be keen to rent off him them. I use loads of rental cars and seldom see one with more than a few 1000's on it.
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We have owned a Peugeot 106 diesel from new and 44k miles - in 13 years. Average journey length 1 mile. Only warms up once a week on a 5 mile journey. Year in year out. A real engine killer..
Oil and filter change every year semi synthetic . And that is it.
Oil consumption between changes nil. Engine untouched - except cambelt changes . and it's a 1.4 diesel - the less reliable one!
We drove a Mini estate that way as well.. Apart from a decoke a similar story. (and that was 1978 to 1992) but using a normal mineral oil as synthetics not readily available then.
So my believe is that annual changes are Ok even on short runs (and remember oil quality 15 years ago was much worse than today's
One point is that in both cases antifreeze was changed every two years or every 5 in the case of OAT specification. I reckon many engine heating and gasket problems are due to gasket or head corrosion caused by weka antifreeze mixtures leading to rapid corrosion - of engines or radiators or both. And how many owners of a car 6-10 years old change the antifreeze every two years?
(Both the above cars orginal radiators were/are in excellent original condition :only changes were hoses and the odd Mini thermostat...)
madf
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"So he runs a car rental company with cars doing up to 100K !! I wouldn't be keen to rent off him them. I use loads of rental cars and seldom see one with more than a few 1000's on it. "
Erm.... and why's that then? Would you not drive a car with more than a few 1000's? Sorry - I really don't understand what your point is...
I've used loads of rental cars and have seen many with up to 100k on them. Only exceptions are the big chains like Hertz and Avis as they're owned by manufacturers (eg Ford & Vauxhall) and change their cars at 10-15k to supply their "approved used" car schemes. Pop down to your local Ford dealership and most used cars up to 2 years old are ex-Hertz rental cars. (although the salesmen almost always come up with some baloney like "they're ex-Ford management cars" or "demonstrator cars".)
Most independant rental firms keep them until the 100k mark, as once a car has been registered to a rental company, it's second hand value is trashed anyway so they may as well get some value out of them. And as has already been stated, they clock up 100k in just 2-3 years max.
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I've used loads of rental cars and have seen many with up to 100k on them. Only exceptions are the big chains like Hertz and Avis as they're owned by manufacturers (eg Ford & Vauxhall) and change their cars at 10-15k to supply their "approved used" car schemes. Pop down to your local Ford dealership and most used cars up to 2 years old are ex-Hertz rental cars.
Hertz are not part of Ford, they are owned by a consortium of private equity companies. Avis (and Budget) are owned by Cendant. They keep the cars for typically 6 months and about 12k mi. They get the cars at a big discount and make a lot of their money by releasing them back into the used market for more than they paid for them. They always service them to schedule. Private customers can buy the cars directly (e.g. for Hertz ring their Banbury office 01295 667000) and they are not a bad buy at all. A rental history certainly does not trash values - they are quite sought-after by the trade, contrary to what many seem to think.
I have never seen any rental company that keeps cars to 100k mi (possibly some truck rental companies do). This must be a very small back-street outfit. I would defintely not want to part with my own money renting a car up to three years old with 100k on the clock that had not had a full service. Seems a very poor way to run a business to me.
Oil does shear down. Typically the valve gear imposes the biggest load on the oil (shear). Big-end and main bearings do not normally suffer if the oil is kept filtered because they are hydrodynamically lubricated. Its the cam and lifters that suffer - cam wear and sticking lifters. I have seen a number of high-mileage VAG cars that have been on variable servicing where the car sounds like a helicopter because the valve gear is clattering away. Timing chains are also susceptible to degraded oil, so if you have a car with a timing chain always change the oil regularly.
I certainly would not go with the 3000mi changes, but a change every 12000 miles at least - its not expensive, especially if you buy from factors and don't pay through the nose.
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Big-end and main bearings do not normally suffer if the oil is kept filtered because they are hydrodynamically lubricated.
What does that mean Aprilia? Over my head but interesting!
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I hope Aprilia doesn't mind my attempt in answering this one.
Hydrodynamic lubrication is where a load bearing oil film is developed purely by the relative motion of the two parts. All that is needed for hydrodynamic lubrication is two parts with the right relative geometry, some oil (the pressure doesn't matter much), and sufficient relative speed.
For cylindrical bearings, when they are rotating and carrying a load, the shaft doesn't run central in the bearing. As the shaft rotates, it "pulls" the oil around the bearing, and the oil pressure is naturally increased in the narrow part of the bearing. The oil pressure varies around the bearing, and the higher oil pressure in the heavily loaded area of the bearing carries the load. It is possible to estimate the minimum oil film thickness in the bearing as a function of load, oil viscosity, and bearing speed. As long as the oil filter can trap particles smaller than this minimum oil film thickness, there should be no metal to metal contact during running.
The necessary geometry is one where the oil is "puled" into a narrowing gap, this enables the pressure to build. Note - there doesnt need to be an oil pump for this mechanism to work. The lubrication mechanism was first discovered by Beauchamp Tower during an investigation into steam engine bearings, which were bearing running in an oil bath, with no pump. The maths of this system were first dealt with in any detail by Osborne Renolds as part of his investigations into fluid mechanics.
So, a well designed hydrodynamic bearing always has an effective oil film there is no significant wear during running. During starting and stopping, you do get some contact, but that's true for all the running surfaces.
Becasue there is more intermittent relative contact for parts in the valve train, the conditions for hydrodynamic lubrication never really get a chance to establish, and so there is more contact, and hence more wear in these areas.
There is a related bearing, called a hydrostatic bearing, which does rely on the oil pressure, but this needs very high oil pressures and this isn't used in car engines.
Number_Cruncher
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Hertz are not part of Ford, they are owned by a consortium of private equity companies.
Ford still have a majority interest in Hertz
A rental history certainly does not trash values - they are quite sought-after by the trade, contrary to what many seem to think.
Nonsense. Glass's online even has a -ve value adjuster for "rental, private hire, ambulance etc"
I have never seen any rental company that keeps cars to 100k mi (possibly some truck rental companies do).
I have. Several in fact.
This must be a very small back-street outfit.
No - not at all. Don't assume....
I would defintely not want to part with my own money renting a car up to three years old with 100k on the clock that had not had a full service
Yes, you've already said that but you (still) haven't said why?. Also where have you got the idea that they weren't serviced properly from?. All that was stated was that they were oil-serviced every 15k, and not in-between. Many manufacturers have in excess of 15k intervals these days.
Seems a very poor way to run a business to me.
Yes, servicing a car according to the manufacturer recommendations sounds really daft. Much better to spend twice as much on servicing by doing unnecessary interim services isn't it. Most businesses succeed by spending money unnecessarily don't they! What school of business did you attend?
I have seen a number of high-mileage VAG cars that have been on variable servicing where the car sounds like a helicopter because the valve gear is clattering away.
I've OWNED (note : not "seen") several VAG with high mileage, that have been on variable servicing, and none of mine had that issue. Can only assume there must be some other cause.
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