Maintenance - neccesities vs. money making

What do you define as "non neglect"? Oil changes at intervals indicated by the trip computer?

DAS

Danny - I'll agree with you on ONE point. Oil analysis can be used to extend oil change intervals on engines running under favourable conditions.

Nobody ever said it "suddenly" becomes unserviceable. It is a gradual process, which generally accellerates at a certain point - which differs from oil to oil, engine to engine, and with operating conditions. When basic oil acidity reaches a certain point, the oil sludges much more quickly, gets "dirty" faster, looses viscosity faster, or thickens faster with heat. Once it starts, it's a relatively fast downhill ride. Vehicles that get short trips at low speeds in extremes of temperature TEND to have this happen sooner rather than later.

Yes, if your driving conditions are basically unchanging - you drive

The point is, people are NOT doing the oil analysis. They ARE neglecting the engines. They are not even THINKING about their oil for

When the oil gets past that nebulous point where it stops doing its job as well as it is designed to, engine damage is caused. That is a FACT that cannot be disputed. When that point occurs is open to question - and how MUCH damage is done, and how quickly varies from engine design to engine design. If you had a 2.6 Mitsu and did not change the oil often enough, and use good enough oil, it let you know in NO UNCERTAIN TERMS. Often while still within warranty.

There are many other engines out there that will do the same. Doesn't matter WHAT manufacturer. You may say it isn't so - but that, my boy, doesn't change anything.

Not nearly as much smoke as some of the engines

That test was severely flawed in several ways. First of all, taxi service, although severe, is oilwize one of the least stressing, as the engine is started in the morning, and only shut off for fueling, if that. The oil comes up to temperature and stays there. Not out of the ordinary for a taxi engine to go half a milion Km without being opened up at all. Also, these engines had been subjected to varying maintenance before the study was started, and several engines failed part way through the test of causes that were not attributed to oil change intervals.

My anecdotal evidence with Toyotas was over a period of 10 years at one dealership, where OUR customers generally followed our directions, and changed the oil a minimum of 4 times a year or every 5000 KM, give or take. Of the vehicles we serviced regularly, we had NO lubrication related engine failures during those 10 years - and precious few engine failures of ANY kind.

We did, however, do a fair amount of engine work, on vehicles sold by other dealers who did not stress the oil change maintenance like we did. By the way, the "small" dealership I worked at had over 600 "active" customers - those we saw on a regular basis for preventative maintenance. Average workload was something around 12 vehicles a day for oil changes (some had other work done as well - tune ups, exhaust, brakes, etc), as well as numerous vehicles in for work not including an oil change. This works out to better than 4 oil changes per year, average, for 600 customers. We had more customers having their vehicle serviced with us than we sold in 3 years - or to put it more accurately, our service retention rate over 3 years was over 100%. (service retention rate is the percentage of vehicles sold by the dealership which were still "active" customers 3 years later.) We had to be doing something right.

On general, their operating costs, including regular oil changes, fluid changes, brake services, etc, was consistently lower than the operating costs of those who chose NOT to listen - as repairs are always more expensive than prevention. IIRC the difference was something close to 10%.

In all my driving years, I've only sold ONE car with less than 100,000 mikes (160,000km) on it. That was a '76 Ramcharger I bought new, and sold to make the downpayment on my first house. That vehicle cost me more per mile both in outright cost and in maintenance, than any other vehicle I have ever owned. Of all the vehicles I have owned, (23 if memory searves correctly)I have only had 4 engine failures - 3 of which were dead when I bought them (2.6 Mitsu in 75 LeBaron T&C, 3.8 GM in 95 TransSport with

- engine overheated in 1962 at 100,000 miles by original owner, and I bought it in 1972) The other one hardly counts - my first car- a 1961 Austin Mini purchaced with 196,000 miles on it, needed rings and bearings before I sold it with 214,000 miles on it. My current 88 Chrysler (3.0 Mitsu) has had the heads replaced twice for valve guide problems. Has about 240,000Km on it now. TranSport has about 306,000, more or less.

I TRY to change the oil every 3 months or 5000 Km. Occaisionally I go an extra month, or an extra thousand KM - and I'm not complaining.

Amazing! Another myth exploded.

Bill Putney (to reply by e-mail, replace the last letter of the alphabet in my address with "x")

Actually, you'd be surprised. I have had the "auto Xray" analyser connected to the Tran Sport overnight in the winter - and parking the van at operating temperature at 9PM, and starting it at 7:30 AM next morning with -10C temps overnight and the truck sheltered from the wind by being parked close up to the garage door, the engine block/coolant temp was often still between +2 and -4 C.

Take the truck to work, and park it fully warmed up at 8:30AM in an open wind-swept parking lot at -5C, and by noon the coolant/block temp would be -4 or -5 C.

It is not wind chill, but the chilling effect of cold moving air is still significant!!!

The jury is still out. On today's GM cars, with the oil analyser built in, the recommended (by the computer) oil changes vary widely - from less than 6000KM to well over 15000. Not enough of these vehicles/engines have accumulated enough time and distance to know conclusively if following the "computer" constitutes adequate maintenance, or abuse.

So it was close to the garage door that transferred and reflected heat from the (warmer) opposite side. If you left it there under the same conditions for several days it would still be warmer - but because of the heat radiating from the garage door warming up the air and the metal.

But that, by definition, is what chill factor is, except with or without wind, an inanimate object that is not producing heat will settle to the exact same ambient temperature given enough time.

In effect, Matt said, it will still asymptotically settle out to the same ambient temperature, but with wind added, it will cool to that same temperature faster.

Here's what he said: "Sure, parking into the wind would make the car cool down to ambient faster, but over the course of a 10 hour night, the engine will be the same temperature in the morning whether parked into the wind or not."

Again, parking next to the garage door affects other things besides simply the flow of air. There is heat radiating from the garage door (from heat inside the building) in your real life example. That certainly would be enough to make a few degrees diffence. Bill Putney (to reply by e-mail, replace the last letter of the alphabet in my address with "x")

No, the garage is unheated. Parking it nose up to a hedge has the same general effect. And sitting over the weekend, rather than 10 hours, the engine block temp was within a couple degrees of ambient, even against the garage (where it sits every weekend throughout the winter)

No, wind chill refers only to exposed skin, where humidity is also involved, as moving cold wind removes humidity from the body as well, reducing body temperature due to the latent heat of evaporation, or some similar scientific explanation.

Correct. Nobody is disagreeing with Matt.

My point was the effect of a cold wind is possibly greater than he suspected.

You've never been inside my garage!!!!!

OK - so your point was the rate at which it cools out in the open vs. with less wind due to the wind being at least partially blocked. No problem. So the overnight settling with the wind blocked just wasn't long enough (it *is* an asymptotic settling, so it would never actually get there in a steady state world). I think we're all in agreement over that.

But the same laws of physics apply to warm inanimate objects as human skin, only differenc being that the inanimate object is not producing heat, the skin is - so the inanimate object cools off faster with wind (vs. no wind at the same ambient temperature), and the skin feels colder

- both are having heat pulled out faster with the wind vs. still air. It's semantics to say that you can call one effect (with skin) "wind chill" and you can't call the other effect (with inanimate objects) "wind chill" - both are *chilling* effects due to the *wind* (at a given ambient temperature).

BTW - humidity has very little to do with it. It's temperature gradient next to the skin due to still air being warmed by the skin vs. constantly replaced cold air pulling heat out faster (creating a much higher gradient). Saying it's due to humidity effects is almost like saying that the sun is stronger in Denver than at sea level because you're a mile closer to the sun. It's predominantly temperature gradient (of air next to the skin) - not humidity/evaporative effects.

Bill Putney (to reply by e-mail, replace the last letter of the alphabet in my address with "x")

I checked - you are more correct than I am. APPARENT TEMPERATURE or WIND CHILL is calculared from a baseline neutral skin temperature of 33C

coined it in a study: "Adaptation of the Explorer to the Climate of Antarctica".

freeze 250 grams of water in a plastic cylinder that was exposed to the elements. The three parameters involved are:

of 33 °C as a baseline value, so only two parameters remain.

replaced with colder air. The factor is an indication of the effect of the combination of air temperature and wind speed on human comfort and safety.

forecast true wind speed;

not be predicted;

hypothermia and frostbite on board!

from

So they should, being dependent on driving condiitons.

DAS

Well, I was sitting in this bus in London next to a man who was tearing up sheets of paper and throwing the bits out of the window.

"Why are you doing this?" I asked.

"To keep the elephants away," he replied.

"But there are no elephants..."

"See what I mean?"

:-) DAS

The oil capacity of my 11-year-old 2-litre car (same manufacturer as my

Drat, I forgot to check if there is any indication of oil consumption.

DAS

The oil analysis doesn't care about the conditions the oil was used under, it just reports what is in the oil.

Got data?

Matt

And I've had virtually identical experience with 5,000 and 10,000 mile oil changes on a range of vehicles from a Chevette, to Chrysler minivans, to an Acclaim, a Jeep Comanche, a Chevy K1500, etc. So, I guess that means that I can claim you are wasting oil and filters and unnecessarily polluting the environment because you are recommending that perfectly good oil be thrown away.

I'll never dispute that good maintenance is cost effective. That is one reason I still do most of my own maintenance. However, changing oil, filters, brakes, whatever, before it is necessarily isn't good maintenance! It is simply wasteful.

So, why are you wasting good oil? :-)

Matt

Actually, it is wind chill. All wind chill is, is a simple way to measure the accelerated heat transfer due to moving air past a body that is warmer than the air.

Matt

There is one particular oil analysist test component (TBN- total base number) that will tell you how well the oil is doing on resisting acidity. The oil dosn't "gradually" become more acidic. It remains neutral to basic as long as the additives are good enough to neutralize acids as they form. As the additives get used up in neutralizing acids, the TBN drops. Its easy to tell from tracking oil analysis results whether the oil will go another 5000 miles or another 500 miles.

That is assuming that the viscosity, particulate numbers, and the trace metal numbers, etc. are still low enough not to be a problem, which they usually are.

Amen to that. One of the things I see in parts houses now that just makes my skin crawl is the shelf full of "loaded calipers." Yep, why bother replacing just the pads on the brakes when you have to take the caliper off the mounting anyway? Replace it ALL!! It comes ASSEMBLED!!!

How *^&@ing gullible and lazy are people today, anyway? A brake caliper is often good for the life of the car, especially outside the rust belt (and even in it, frequently). At WORST, its probably good for 3-4 pad changes.

What a waste, and that's just a randomly-picked example.

Me three. "Sir, your front brake pads need replacing, and your rears are down to about 40 percent life remaining, so you should replace them, too" is just like your doctor saying "OK, you're 55 years old? That means you're down to about 40 percent life remaining, so if you'll just hold still I'll shoot you now."

Yep, what a load.

Gullible enough to fall for "Well, your condenser has a leak, so you should replace the evaporator, too, and probably the radiator as well".

Lazy enough to have no problem with "It's easier to replace two parts unnecessarily while replacing one necessarily than it is to replace only those parts that have failed."

Indeed.