Don't like the time between oil changes

Page 3 of 4  


So how did you arrive at the 5000 mile figure? Hold your fingers up to the light?
--
*Speak softly and carry a cellular phone *

Dave Plowman snipped-for-privacy@davenoise.co.uk London SW
  Click to see the full signature.
Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload

Makes good sense. I have a X5 that I put less than 10K miles a year. Mostly stop and go driving. The Oil Service Indicator never goes to orange; however BMW does an interim "low usage" oil change. Even so, the oil (after about five months and 2K miles) looks dirty. I realize "looks dirty" does not mean anything technical. However, I am tempted to do an oil change anyway. Yes, I realize it is my money and if I want I could go ahead and change the air in the tires too.
On that note, I read about a service station that is pumping pure nitrogen (99%). Charges $7 per tire. Is that also another gimmick or is there any sense to it?
Kind regards
gamini
Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload

There is some sense to it. Dry nitrogen has (obviuosly) no oxygen or water vapour in it.
Oxygen can attack the rubber, causing some degradation over time. However, this happens to the outside of the tire no matter what you do, so minimizing it on the inside doesn't hurt but probably doesn't help much.
Nitrogen is a slightly bigger molecule than oxygen, so it diffuses through the rubber more slowly. All other things being equal, a nitrogen tire will loose pressure slightly less slowly than an air one. But air is ~78% nitrogen anyway, so that's also not a huge effect.
The biggest one, as far as I know, is change in pressure with temperature. Air contains some amount of water vapour, which apparently changes pressure with temperature more than straight nitrogen (I don't know how the thermodynamics behind that work). In theory, a nitrogen filled tire will maintain pressure more evenly than an air filled one.
I suspect this whole idea got piggy-backed off the airline industry, which does fill their tires with nitrogen. But they do that because, if they use air, the tires will explode under certain situations. No car tire operates that hot, so it's not really applicable.
Tom.
Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload

And I'll bet the sprite still needed a re-bore at around 60,000 miles. There's absolutely no hard scientific evidence that changing oil early extends engine life.
--
*Born free - taxed to death *

Dave Plowman snipped-for-privacy@davenoise.co.uk London SW
  Click to see the full signature.
Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload

Actually, Dave, that's not accurate. If you go Google "Toyota oil gel" you'll find a bunch of stuff. Now, Toyota says it's people going beyond the oil change intervals. However, Toyota also says 5K miles for heavy-duty use and 7500 miles for light-duty so owners often don't know which regime to follow. It's clear that oil change intervals matter, but what the interval should be is a matter of conjecture.
BMW is conjecturing (with good reason IMO) that 15K miles synthetic changes in their engines is adequate. If you could answer the question: "why 5/7.5K for Toyota and 15K for BMW", you would have my attention.
Of course, one reason would be the quantity of oil used: Toyota uses only 3-5 quarts while BMW uses 7-8. But that's probably not the only reason; the Toyota critics allege that since the gel problem only occurs in specific engines it's a design fault that can be masked by frequent changes.
Bottom line: there's no hard scientific evidence that changing oil at 15K intervals in BMWs is best for long engine life.
FloydR
Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload

So where's your evidence that cars serviced by the indicator suffer reduced engine life? Despite reading a lot about BMWs I've not read anyone reporting engine problems down to worn out or contaminated oil. Which would surely be common if it *were* three times the 'correct' amount. And the BMW service indicator does take into account the type of usage which fixed intervals don't.
--
*It's lonely at the top, but you eat better.

Dave Plowman snipped-for-privacy@davenoise.co.uk London SW
  Click to see the full signature.
Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload

My 2 cents:
With today's modern engines and lubricants, it's unlikely an engine is going to "wear out" during the warranty period regardless of whether the owner follows the factory recommended oil change intervals or has it changed more often. After the warranty is over, the manufacturer wants you to buy a new car.
If you are trying to get 2 or 3 times the warranty life of an engine, then changing the oil more often makes sense. If not, you are wasting your money.
Eisboch
Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload

But I don't buy new cars and often run them well beyond any warranty. My last BMW was at approx 150,000 miles when I sold it (E34 525 24 valve) and that was in rude health. The 'specialist' that bought it from my dealer clocked it back to 70,000 so must have thought so too...;-)
My previous one, an E28 520, now belongs to my brother and despite a hard life towing is approaching 250,000 miles. The bodywork will see the end of that car - not the engine. It's still sweet and burns no oil.
IMHO there are very very few people who buy a car new and run it to high miles - apart from business users. And business users are the ones long service intervals are aimed at. If service intervals are marginal you're bound to increase the overall failure rate. Exactly what business users won't tolerate.
--
*'Progress' and 'Change' are not synonyms.

Dave Plowman snipped-for-privacy@davenoise.co.uk London SW
  Click to see the full signature.
Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload

Only if the oil degrades significantly between the change intervals. If your synthetic provide sufficient protection at 10,000 miles, then changing every 8,000 will make absolutely no difference to your engine life.
The engine "wears out" due to loss of metal. That can happen chemically or by metal-to-metal contact. Chemical attack is a function of how well the oil neutralizes contaminants...that does decline with age, but there's a lot of factors that play into that that are more important than just age. Metal-to-metal contact is a binary thing...you either have it or you don't. If you don't, then it doesn't matter if your oil is brand new or 15,000 miles old.
The oil does suspend metal particles that have come off the engine. However, if the filter is working properly, none of the particles in the oil are big enough to damage anything, so who cares?
Tom.
Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload
wrote:

and the small particles that are too small to be captured by the filter, but do discolour the oil, float harmlessly withing the film of oil as they pass through bearings, which is why the colour of the oil is unimportant unless it varies from the norm for that engine at that service interval. Anyone who has ever had and maintained a diesel engine will know this.
Huw
Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload

A diesel's oil gets black within a few hours after changing it. Typically an oil analysis is done from time to time to indicate abnormal wear of the engine. (This is the case of marine diesels, anyway ... I don't know about automobiles).
Eisboch
Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload
Eisboch wrote:

Hardly anyone bothers with cars. They just change as indicated in the owners manual. As you say, the oil in many diesel engines gets jet black with dirt within minutes [no exaggeration] of changing for fresh oil. This is quite normal and doesn't stop diesel engines living a long and productive service life.
Even my old indirect injection land rover diesel engine lasted over 22 years until last night when it finally expired with a bang. Its oil always had a filthy dirty appearance yet it lasted over 12,000 operating hours which amounted to 140,000 miles of short journies, many towing up to an illegal five tons [allegedly;-)] while carrying a ton payload. Not bad for a 67hp 2.5 old technology engine revved to the governor routinely.
Huw
Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload

The USA has been slow to embrace diesel power compared to Europe. In fact, for several years the emission standards for diesels were such that no diesel powered new cars subject to emission testing were available from US or European manufacturers. Within the past couple of years new models that meet the emission requirements have become available. I became a believer when I purchased my first diesel powered boat and now drive a diesel pickup truck as my daily driver. Ultra-low sulfur content (15 ppm) diesel fuel became mandated here in Oct (replacing the low-sulfur fuel of 500 pmm). It definitely burns cleaner and I've noticed that the occasional "whiff" of diesel exhaust smell has completely disappeared.
Eisboch
Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload

Yes they have removed the aromatic compounds as well as sulphur. A by-product of reducing sulphur is, as you say, less soot through the exhaust and combined with direct injection engines, less soot in the oil as well. This is partly the reason that some European diesel engines can run far longer between oil changes than petrol engines from the same manufacturer. For instance, some VW and GM diesels can go for up to 30,000 miles between oil changes. Yes, its worth repeating for those that change their oil every 3000 miles, 30,000 [thirty thousand] miles between oil changes.
Huw
Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload
I am afarid you'll be shouting at a lot of deaf...
DAS
For direct contact replace nospam with schmetterling
--
"Huw" <hedydd[nospam]@tiscali.co.uk> wrote in message
news: snipped-for-privacy@mid.individual.net...
  Click to see the full signature.
Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload

You didn't read any of the Toyota stuff, did you? A clear case where overly-long oil-change intervals caused premature engine death. Yeah, we're on a BMW group, but evidence is evidence.
FloydR
Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload

I didn't. Your summary was enough. The BMW service indicator takes into account the type of usage and the handbook mentions a timed (not mileage) change for extra low use cars.
--
*The longest recorded flightof a chicken is thirteen seconds *

Dave Plowman snipped-for-privacy@davenoise.co.uk London SW
  Click to see the full signature.
Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload
Dave, do you like banging your head against a wall of finest London brick?
DAS
For direct contact replace nospam with schmetterling
--
"Dave Plowman (News)" < snipped-for-privacy@davenoise.co.uk> wrote in message
news: snipped-for-privacy@davenoise.co.uk...
  Click to see the full signature.
Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload

Yup. It's one of my few pleasures. ;-)
--
*A plateau is a high form of flattery*

Dave Plowman snipped-for-privacy@davenoise.co.uk London SW
  Click to see the full signature.
Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload
I haven't yet read the Toyota oil thread either, but you did say the ref was to drivers exceeding the recommended interval.
With my 1986 W123 230E (ok, ok, a Merc, but same difference...) I followed the (fixed) recommended intervals and it ran fine for 120 000 miles and 6.5 years till I had to ret rid of it (my company decree). Continued fine service until one of the subsequent owners bent it beyond economic repair.
DAS
For direct contact replace nospam with schmetterling
--
"Floyd Rogers" < snipped-for-privacy@hotmail.com> wrote in message
news: snipped-for-privacy@corp.supernews.com...
  Click to see the full signature.
Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload

Related Threads

    Motorsforum.com is a website by car enthusiasts for car enthusiasts. It is not affiliated with any of the car or spare part manufacturers or car dealers discussed here. All logos and trade names are the property of their respective owners.