The big killer is combustion byproducts. Since engines are a lot cleaner burning than they once were, this is reduced somewhat. The manuals on my cars recommend 7500mi for light service and 3000mi for severe duty. Look up the meaning of "severe duty" and it includes pretty much everything except non-stop interstate driving in 70F, dry, weather.
Most cars come with stainless exhausts now - and those that don't - put them on at first replacement. My first Aerostar exhaust went at about 30 months - the replacement stainless lasted untill the guy I sold it to scrapped it at 300,000km, about 15 years or so later.
My SS exhaust went after 9 years (
There has been one MAJOR change in automotive engines/oil over tha last 40+ years. And that tis the introduction of lead-free gasoline. That is the only MAJOR change that has worked to make extended oil change intervals viable, because with unleaded gasoline there needs to be less Phosphorous and other additives to keep the lead from forming harmfull deposits. This reduction has reduced theacid level in the crankcase - allowing the buffer additives to last longer (which allowed the oil companies to add less to the oil, getting you back, basically, to pretty well the same point.
The other, lesser change, was the introduction of fuel injection, which controls fuel mixture better and reduces fuel dilution of the oil - which allows winter change intervals to more closely track warm weather intervals.
For short trip, widely varying temperature and humidity conditions,
3000 mile 3 month oil change intervals still make some sense. These conditions constitute "extreme" duty - as do trailer towing or extended high speed high load operation. Aproxemaetly 30-50% of north american driving falls outside of these parameters, making extended oil drain periods acceptable.My car generally drives 3-5 km at a time, 3 times a day, 5 days a week, with an extra 15Km twice a day (one of those days)once a week and an occaisional 100km drive every couple of weeks. Every couple of years it gets a couple thousand KM put on over a 2 week period. 5000km (3000 miles) is 5 months of winter driving, and 7 of warm weather driving in a normal year.
My wife's car got about half as many trips of the same length per week, and mabee twice as many 100km trips, with one 3000km trip over the last 9 years. It's 16 years old and just turned the 160,000km (100,000 miles) 2 weeks ago - for an average of 10,000km (6000 miles) per year with 60% or more of those miles in the first 5 years, before we bought it.
Is 2 oil changes a year per vehicle a waste of time, money, and other resources??????
I think not.
I hope yu have advised the auto makers world wide of this remarkable requirement. They need to change their manuals ASAP.
Harry K
This is true! Or 'light service' could be described as 7,500 miles, all run in one 'trip', on a dyno, mounted in a clean room. Not 'real world usage...
Rant mode on:
Modern conventional oil's don't 'break down' in short trip usage, but rapidly becomes more and more contaminated with water and acids... leading to bearing deterioration, sludge issues, and hardening of seals. Note that modern oils are still wonderful lubricants even after being run well beyond their recommended change intervals... it's contaminates that are the issue. (Dirt becomes more of an issue if the oil is run long enough cause a filter bypass to open, or if you get a bum oil or air filter. Modern oil and air filters are for the most part very good.)
If your 'average' trip is on the order of more than 20 min or so, oil will routinely reach sufficient temperatures, and maintain them long enough too boil off most (but not all) contaminates. These are eliminated by the PCV. For 'long' trips, yes, 5 or 6 thousand miles change intervals are fine.
But if your normal usage is short (or dusty) trips, contaminates rapidly become more and more concentrated. It's here where you should do changes every 3,000 miles, OR 90 DAYS, which ever comes first! 90 days as in actually marking it on the calendar, and ignoring the odometer unless it's racked up over 3k miles!
Remember, that water and acid are continuously at work, even when the vehicle is just sitting parked. (Expensive synthetic oils contaminate just like conventional's by the way.) 3k change intervals also minimize dirt issues in the event you happen on a a bad oil or air filter too... it happens on occasion.
If you don't care about the car, or trade every couple of years, run it as long as you want! On the other hand, you can get a LOT of dependable service out of most any engine by regularly changing oil. (Do the coolant every year too... that's a rant for another day.)
Four oil changes a year isn't that big a deal...
Rant off.
Erik
On 8/26/2011 5:53 PM, Metspitzer wrote: (snip)
While I mostly agree with you in principle, I'm afraid that ship has long since sailed. A whole lot of what the government buys is no longer made in this country, period. The factories aren't even THERE anymore. Congress did pass the so-called 'Buy America' act several years back which tried to require what you advocate, but I'm not sure they even try to enforce it any more. Try to buy a computer (for example) that isn't mainly China or Pacific-rim sourced. And the gummint buys a Whole Lotta computers.
They already have.
Rant all you want, but the truth does not bear you out. Yes, some people should change at 3000 miles, but most would be wasting their money. Some others should change at 5000 miles. I know of plenty of cars in the
100,000 to 200,000 mile range with no engine problems at higher intervals. The people that warranty my engine for 100,000 miles would not tell me to change at 75000 miles if it was going to cost them money.Sorry, you were right 40 years ago, but not in 2011.
Did you buy the car?
I don't know how often the oil was changed on the Grand Am my daughter bought with 120K on it. I *do* know that for the next 120K she changed the oil when the car told her to. [probably 5-6-7K]
At 240K the suspension & body were beyond her comfort level so she traded it in-- but the engine in that thing was perfect.
I've pretty much 'waited for the light' since 1995 when my Taurus had one. When the light hadn't come on for 5k the first time I checked with my mechanic & he said the computers in modern cars are smarter than the drivers- listen to them.
The Taurus got traded when the transmission got unbearable [150k or so] -- The impala has had the same treatment and is at 130k and never uses oil.
Jim
-snip-
I just got a rumble in my 2001 Impala at 126K & went to see when the last time I had replaced the exhaust system. Never. [I did get a muffler 5 years ago] So I crawl under to see what I'm up against. I need the $6 chunk of pipe that adapted from the muffler to the exhaust. [and a rubber donut, and a hanger]
That's another one of those un-noticed advantages of our 'overpriced' modern cars.
How many 'routine maintenance' jobs are no longer necessary- oil intervals, spark plug intervals, points, condensers, tires, batteries, exhaust systems. . .. .?
Jim
Used to do spring and fall full tune-ups to keep mine solid. You forgot carb choke adjustment. That all ended in '91 when I bought an '88 Celebrity with 2.8. Never picked up my timing light or dwell meter again. World of difference after electronics and fuel injection. Nobody much talks about, but I guess metallurgy is the biggest contributor to engine longevity, not newer oils. Not needing valve jobs and no cylinder blow-by makes me think that. You could keep the old ones tuned and change the oil every 2000 miles, but valves and rings/walls would go bad before 100k miles. At least that was my experience.
--Vic
"Jim Elbrecht" wrote
Your experience is much the same as mine. Engines today are incredibly good compared to the rest of the machine. Automatics transmissions are far better than the old Power Glide, but still not as good as the typical engine.
I bought a LeSabre in 2001. I really like that car for the first 40,000 miles. Then, heated seat was first to go. Dealer wanted $675 for replace it. Both rear windows had broken mechanisms and would slide down so I propped them up with wood braces. Brakes lines rusted out, transmission was rebuilt, climate control went nuts. Cold on one side, hot on the other and varied with the heat or AC. Wheel bearing went, a $300 repair. A few other not serious but annoying problems happened.
Gave the car to my grandson after 10 years, but the engine still ran smooth as the day it was built.
Besides which, the concept is flawed. Buyers should be able to get the best value for their needs, irrespective of its origin. In the case of, say, China, we (individuals or governments) buy computers from them because that product is the best value for the price. They, in turn, buy stuff from us (wheat, airplanes, Hello Kitty products) because they, in turn, get the best value.
Artificial restraints of trade ("Buy American", tariffs, taxes, "prevailing wage" rules, etc.) and various forms of protectionism are an overall drag on the economy.
In his book, "An Inquiry Into the Wealth of Nations," Adam Smith illustrated a cheese-wine dilemma. France made excellent wine and mediocre cheese. Just the reverse was true for Italy. France instituted a severe tariff on imported cheese to protect its domestic cheese-makers. Italy did the same with wine. The consumers in France ended up with ghastly cheese while the imbibers in Italy had to drink terrible wine.
The only people who benefited were the makers of indifferent cheese in France and the incompetent vintners in Italy.
Tariffs and protectionism work well when a country has industrial policy. We have none. No energy policy, no industrial policy. Just dopes fighting in Congress and a President with no real policy vision I can see. That's why unemployment is so high, and will worsen.
This economy? Looks like it "drags" just fine all by itself, with essentially laissez faire trade policy and no industrial policy. Hey, that reminds me,
Adam Smith is dead, and so is the pastoral world of yore. I can make my own cheese and wine. For most manufactured goods I have to buy foreign. That's why "they" have jobs and we don't. It won't last though. People without jobs can buy nothing. Unless the Fed can somehow keep printing money to pass out. It's all a dream within a dream. It was good while it lasted.
--Vic
You can pretty much cont on being able to drive 200,000km on a new car with nothing more than tires, brakes, oil changes,a serpentine belt and one set of spark plugs - if you put the miles on fast enough.
Possibly a couple of wheel bearings or CV joints, and a timing belt if it has one. Even the hoses often last that long.
But if that car has not had preventative maintenance, anyone buying it at that point can be in for a whole world of hurt.
Without antifreeze service, the rad is most likely finished. The fuel pump is on borrowed time if the fuel filter has never been changed - the transmission is ready to die if the fluid has never been changed - it will likely need all the front end joints and rubbers replaced, and if the oil has not been changed on an "adequate" schedule the chain tensioners (if it has a timing chain) are "done" and the valve lash adjusters and variable valve timing apparatus are likely ready to call it a day any time as well. If the plugs were not changed on time it might need a new catalytic converter to pass the E-Test too.
The metalurgy has not advanced very much at all over the last 30 years - and in some cases has gone backwards. The newer oils, in many cases, are no "better" than the old oils - in some ways, even worse (less EP additives, for instance), but the engines last longer because of the removal of lead and all the required dispersant additives from the fuel, and the much better fuel control of EFI. A lot less acid buildup in the oil, and a lot less fuel dilution of the oil, which translates to a lot less oxidation of the oil - less carbon buildup in the oil, less corrosion of bearings and rings, less varnish build-up etc.
As for tolerances, the bearing clearances, in absolute terms, have also not changed - but the consistancy and surface finish have improved a lot. Both on bearings/journals, cyls/rings, and combustion chambers. This means a LOT less wear - Untill the additive package in the oil is exhausted, allowing the oil to oxidize and the bearings etc to etch -and the rings to stick, and sludge to block the oil galleries, and all the other nasty stuff that Chrysler, Honda, and Toyota had to deal with over the last decade with the "coking" problems that have been in the news.
The ONLY thing that causes those problems is failure to maintain oil quality - either inferior oil in the first place, leaving the oil in too long, or both.
Theinfamous 2.6 liter Mitsubishi "hemi" in chrysler products a number of years ago did not have oil burning or engine rattling (timing chain ) problems if the oil was changed often enough. The Chrysler 2.7 V6 did not have coking problems and pre-mature failure issues if the oil was changed "often enough" Likewize with Toyota and Honda.
If you drove the car under what the manual identifies as "severe conditions" (90% of urban north american drivers do) and went by the "normal" schedule, you had grief - almost guaranteed.
Friends working in all 3 dealerships report that the've never seen an "overmaintained" vehicle in for any of those issues. NEVER.
"Overmaintained" meaning a minimum of 2 oil changes a year and a maximum of 6000km per oil change.
And while you're at it, don't forget to change the air in the tires. You SHOULD change the air in your tires every 3,000 miles, unless you live in the inner city, where there is pollution, and then 1,500 is advised. In some metropolises, daily changes are suggested.
HTH
Steve
"Ed Pawlowski" wrote
Are you saying things have changed in a mere forty years?
Steve
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