Bob Rouleau

Mac, so much for my hypothesis. Sounds like the idea of not worrying about replacements during the warranty period is the right one

997, esq

Or, conversely, the previous, shorter service intervals were calculated more to generate revenue, whereas the intervals more accurately reflected what was necessary when the manufacturer started picking up the tab.

FWIW, I reject both explanations. Rather, I think that increasing intervals are more a function of improvements in synthetic oils. (Audi, for instance, used to offer free maintenance in the early part of the decade, then they stopped offering free maintenance in the middle part of the decade. The frequency of recommended services didn't increase when they stopped offering the free maintenance.)

I don't think increasing the frequency of service intervals in a street car does anything other than increase maintenance costs and waste time. There's no evidence of increased engine, transmission life with additional fluid changes. Even if an engine or transmission fails at 100K miles, it still leaves a bad taste in the mouth of owner of the car at that time and isn't likely to build brand loyalty. If additional fluid changes markedly reduced the chances of such failure, I'd fully expect a manufacturer to recommend additional changes. Intentionally built in obsolescence wouldn't appear to be a good approach to making big ticket durable goods.

cello

I do as well.

The above is the rub. All manufacturers internally have decided upon a minimum "useful life" for their products. The components composing the product are engineered to last 'at least' that long. If they last longer, fine. But the goal is to set the warranty period sufficiently short of the useful life so as not to risk too much capital under the same. Remember 'warranty' is part marketing (with the other part being legal) as no manufacturer would give one (and swallow its attendant costs) if the other guy wasn't.

What has separated Porsche from other car manufacturers is that its historical view of its product's "service life" was very similar to its customers: The company 'philosophy' was to engineer/build a performance product with a long useful life. Some of the push back by Porsche owners recently deals with the fact that the company seems to have strayed from its historical view and moved toward a more mainstream manufacturer view of product useful life. For example, there is presently a thread on the 997Turbo Forum re Porsche's movement from the trusted GT1 block to the new A91 block with this very issue at its core, imho.

Put a gun to my head and say "call it", and I think that Porsche's current servicing intervals are too long for buy and hold enthusiasts that use their cars; but fits perfectly for those who do not use them (garage queens) or those that turn over their cars every few years (whether buying or leasing). The cynic in me says that Porsche has studied its customer base here and is simply playing the statistical averages as to owner types ...

Clifton

Given that every car is used differently, short trips, track cars, highways/autobahn, garage queens etc., I've always suspected that manufactures use broad strokes. The one recomended oil service for all approach to satisfy the minium.

That is a big reason that pushed me to get oil analysis on my cars, to help me define what the interval really should be for each of their applications/usage.

Every analysis report, no matter how each car is used, has come back short of the broad recomendation for the masses.

OCBen

I'm sure manufacturers have already performed long term testing of the "low maintenance" schedule on a sufficiently large statistical sample size to confidently arrive at the recommendations they've made.

It would be absurd for them to make this recommendation without knowing beforehand how it will play out in the long run - the useful life of an engine.

Bob Rouleau

Ben,

I think the point is what the manufacturer has decided is the "useful life" of the engine. If say, 100,000 miles then longer oil change intervals may have little effect. For the guy who wants to eek out 200,000 miles, perhaps it makes a difference?

Clifton

Agree - I experimented with synthetic vs mineral oil. Synths without a doubt last longer, even under extreme usage, i.e., track duty.

From what I've found synths almost double what mineral can do, no matter how extreme or how they are used. The constant for both, the harder you use them the sooner they breakdown and need to be replaced


I would have to disagree here. Depending on what is being defined as 'additional fluid changes', engines/trans will always benefit from fresh oil changes (insert BMW lifetime oil here). Of course there are diminishing returns and there is evidence that suggest changing the oil too often can even be harmful.

The trick is finding what frequency works best for a motor's specific application.

OCBen

Good point.

But wasn't Toyota bragging in their commercials about their engines lasting a million miles, the so-called Million Mile Club?

Saab had a campaign (don't know if they still do) where they give a free car to any owner who achieves a million miles on the original engine!

http://www.autoblog.com/2006/12/18/s...ion-mile-club/

So I'm guessing the useful life of an engine, from a manufacturer's perspective, would be closer to 500,000 miles than to 100k. So I'll guess 300k. I know I had over 300k miles on my 300ZX on the original engine, and I abused that car, not babying it all.

Clifton

Exactly. Additionally, think about the brand's image....Even if you never own a car beyond 100k, the allure of many cars is knowing that the quality is there and that theoretically it could run "forever".

The downside I see of new low maintenance cars is that maintenance costs outside of warranty could exceed the incentive to own a older car of that brand. If no one wants to own a prestigious higher mileage car, then resale drops. If resale drops, new cars won't hold their value and depreciate even faster when you drive them off the lot.

OCBen

Well, that would contradict your premise, wouldn't it? That dirty oil is harmful to an engine?

How could it ever be harmful to have clean oil in the engine at all times?

As a sanity check, view the oil circulation system as an open system instead of a closed system. Meaning fresh oil flows into the engine (after being preheated to engine temp) flows through all the components and flows out the engine, taking away all the byproducts of combustion and all the accumulated debris along with it. That would be the ideal oil circulation system in the abstract.

Clifton

Take a wild guess what the oil interval set by the Toyota Motor Co. is.....5,000 miles. They experimented with higher levels and failed.


Saab upped their intervals to 10K - funny they stopped the million mile giveaway. How odd....

OCBen

I'm taking a wild guess that you don't have a source for your claim here.

A link will suffice.

How odd that you would post without getting your facts straight. Oh wait, not odd at all really.

If you had bothered to read the article you would have learned that it was a one time offer in 2007. It had nothing to do with their engines not living up to this standard, as your comment implies.

OCBen

I'm taking a wild guess that you don't have a source for your claim here.

A link will suffice.

Clifton

Company spokesman Bill Kwong

vexed

I changed my oil today, 2550 miles. I did it because I thought it was a good idea since I do too many short trips. You can see the filter was dark but not black. I tried to get a pic of the oil left in the housing, did not come out too well.

My biggest challenge is my drain pan fit under the oil pan but with no clearance for me to undo the drain bolt so I had to jack the car undo the bolt and then let the car down. It takes a loooooooooong time for the oil to drain. Also you need to press the filter down into the housing, the opening will look smaller than the one you are removing because it opens as you fit it in.

Our 2006 CR-V calls for oil changes every 5k miles.

After this I will probably go back to 1x/year.