Oil Change Milestone

FROM: Ryan [E-Mail]
DATE: Thursday May 26, 2005 -- 10:13:53 am

From everything I've read, 5,000 is definitely the number to use for regular cars. The 3,000 limit really only applies to cars like taxis and police cars that are driven hard.

It's all a big conspiracy by Jiffy Lube!

FROM: jk
DATE: Thursday May 26, 2005 -- 10:37:26 am

You chose that link to Car Talk because of the vegan peppermint patties, right?

FROM: Terry M.
DATE: Thursday May 26, 2005 -- 1:34:13 pm

Guys, you need to take a look at the Jiffy Lube ads in foreign countries. There they say get one every 3000 km. That's every 1800 miles!! Sure some countries have rougher driver conditions, but Jiffy Lube seems fixated on the number 3000, regardless of unit of measurement.

Anyways I have 2 cars, one I drive about 3000 miles/month (almost all highway), so I take it to Jiffy Lube every month, which is probably over kill, but it has 204K miles and is still going strong! The other one is new and I drive it very little, maybe 100 miles/month, so I take it to the dealership every 3 months (i.e. usually around 300 miles), which is probably overkill also, but I figure it's better safe than sorry. So my policy is 3000 miles or 3 months, whichever comes first.

FROM: Ryan [E-Mail]
DATE: Thursday May 26, 2005 -- 3:31:50 pm

Then there's the stories you see in the newspaper that talk about the guy who gets 1,000,000 miles on his car and attributes it all to daily oil changes.

FROM: Joseph
DATE: Thursday May 26, 2005 -- 5:34:11 pm

It's all a myth. If you have a car that lasts more than ten years, parts dry up. Even domestic car part stocks are not infinite. If you're lucky to have bought a classic, then the aftermarket industry fills in gaps--but even my common VW Jetta from 1986 has forced me to go fumbling around in junkyards for the most basic of parts, and that was five or six years ago.

For example: New hood release cable--no way to get it but through the junkyard. Also, the there was a transmission bearing that I had to have made specially by a bearing shop. The dealer didn't have it and couldn't get it--forget about the parts store with that kind of part for this kind of car.

Sometimes dealers won't have parts listed, though you know they have the part. This happens more with foreign cars. For example, my Renault Alliance used Ford rear drum brakes, the same as on a Ford Tempo from the same production year. No auto parts stores listed Renault brake parts as available, even special order. I bought the Tempo brakes (I knew they were the same because my girlfriend had a Tempo). Just to be sure, I lined them up--all the markings were the same as well as the pad thicknesses. But other parts became scarce and even though the car was still running strong, electronic parts were nonexistant--even though they were made by GM!

It's fun to make a car last that long, but after a while, ten years or so, you'll have to go hunting for parts anyway. You can't win.

FROM: Merle [E-Mail]
DATE: Friday May 27, 2005 -- 3:29:27 pm

Wow. I've yet to actually reach the 3,000 mile mark.

Of course, I live 1.5 miles from work, and there's a bus for days I don't want to walk. ;-) So my eight year old car has almost 23,000 miles on it..

A coworker just went in for an oil change, and was told "oh, you don't need one yet; these synthetic oils last for 6,000 miles, at least". It was the most bizarre thing. I mean, a mechanic *refusing* work?

FROM: Joseph
DATE: Sunday May 29, 2005 -- 12:23:37 pm

Synthetic oils are rated for 25,000 miles/one year because they don't suffer thermo-viscosity breakdown--they just get dirty. So if the mechanic gets your friend in every 6,000 to change the synthetic oil, the mechanic is actually creating more work for himself, since the car can go four times that interval without a change of oil being necessary. In short, your friend is still getting hosed.

Now, before I inspire a bunch of "you are a dumbass" replies, 25,000 miles/one year per change is a claim made by AMSOIL, which is one of the oldest manufacturers of synthetic oil on the planet, and they are considered to be highly reputable. If you buy Mobile One or Castrol Synthetic, you will notice that there is no recommended oil change interval stated on the container, unlike conventional oil. At least, that's how it was a few years ago when far fewer cars came from the factory with synthetic oil standard.

No one really knows how long you can leave synthetic oil in an engine. Since it doesn't break down from high engine operating temperatures, dirtiness is the main factore. I assume the interval would be different for every car depending on the engine's design and ability to keep crud out of the oil pan. The more piston rings, the cleaner the oil, but the more drag on the piston--it's a tradeoff.

Of course, the interval for conventional oil is really unknown as well, and depends on the car. Changing the oil every 3,000 miles is a lowest common denominator setting. Basically, you are performing against a preventive maintenance schedule based on the strain put on a car when driving in the sand-blown desert Paris-Dakar race.

Something most people don't know: Odometer reading means nothing. You have to know whether the car is driven mostly on the highway or in the city. City driving is the killer because everything wears out faster.

Highway driving, while it may rack up miles, is relatively stress free on a typical car.

Luck has a lot to do with it too. You can religiously change the oil every 3,000 miles and baby the car, like my dad did with his 1984 Ford Escort, only to have it die two years later because a stainless steel cooling line rusted through and expelled all of the engine coolant onto the freeway. (Apparently, Ford didn't quite figure out that stainless isn't supposed to rust). The engine was dead in about ten seconds once the line broke. The value of the car went from $5,500 (sold new for $6500 in 1984) to $100 in that ten seconds. The body was mint.

I run conventional oil in my 1996 Plymouth Breeze. It has 110,000 miles on it at present. Our 2004 MINI has Castrol Syntec in it from the factory, which the dealer will change every 10,000 or so. But, there's a false sense of security there because you must keep monitoring the oil level. I checked the oil on the MINI at 15,000, only halfway to its second oil change, and found that it was a 1/2 quart low--so I had to go buy some and top it up.

The jury still seems out on whether conventional cars even need synthetic oil. For your reading pleasure, I will direct you to a study that compared synthetic oils. You will notice that because the viscosity of the synthetic oil remained high, the oil change occurred on the time interval rather than the mileage interval. The time interval, to me, is based on the "better to be safe than sorry" philosophy, as the study didn't show that the oil actually went bad. But they changed it anyway.

The most interesting result I find from the study is that a blank equal interval cycle doesn't seem to address engine longevity the best. This study supports the idea that during engine break in, which seems to be the first 20,000 miles (of the vehicles tested, anyway), oil changing should occur more frequently. The first oil change should actually occur at 1,000 miles. I'm not surprised by this. This is how they used to do it from the beginning of cars until, I'm guessing, the 1970s or so. I'm not sure when that stopped, but they don't really do it anymore. The reason may be because the damage done to an engine by not changing the oil after the first 1,000 miles is still miniscule and nothing to worry about. The damage may have been more significant in the old days. I don't really know.

So there you have it. Who really knows?

FROM: wolfdog
DATE: Monday August 15, 2005 -- 11:04:34 am

I have a new 2005 Honda Civic. The dealer tells me the car has breakin oil in it and not to change oil until 10,000 mile. I would like to get Mobil 1 in there like at 1,000. Any thoughts?

FROM: Stuart [E-Mail]
DATE: Thursday September 15, 2005 -- 7:39:54 pm

I talked to the dealer and they told me the car has breadin oil and not to change it till 5000 miles. They said a synthetic oil would be put in at that time.

At 500 miles I am only getting 22 mpg in the city and 32 hwy with my 2005 honda civic ex special edition. Any feedback would be welcome on the gas mileage would be appreciated.

FROM: Stu
DATE: Thursday September 15, 2005 -- 9:06:23 pm

I religiously changed the oil on my 94 Saturn every 3000 miles (give or take a couple hundred). Still, after 11 years, it's only got 95000 on it, but it's wearing and tearing like an old car. The head gasket went, power steering pump leaked, valve opening/closing arm broke, new alternator, pretty much most of the car in the last couple years. Not sure why I kept it, but have so far. Dealer puts high-mileage oil in, not because it has high-mileage, but because all the parts are 11 years old now. When I buy a new car, I think I'll still change it every 3 to 4. New oil can't hurt, and it's not that expensive to do.

FROM: JC
DATE: Sunday September 18, 2005 -- 9:23:17 pm

Has anyone seen the Mobil Clean 5000 oil? It is guaranteed for 5000 miles between oil changes - but only costs $1.89 a quart. nice.
They have also donw a Mobil 1 that is guaranteed for up to 15,000 miles - but that costs three times as much!

FROM: M
DATE: Monday September 26, 2005 -- 3:52:52 am