Oil Changes

I’ve been using the 5k oil change interval for almost 20 years now. My wife and I have two completely different commutes. Mine is mostly highway and hers is mostly back roads and stop and go driving. I change the oil in both vehicles every 5k miles. Wife’s first Accord went well past 300k miles without a single engine problem…Her last Accord we sold at about 240k miles and the engine was running great…My 2 pathfinders during that time frame went well past 300k miles and engine’s were fine. 5k oil changes is about the max I’m willing to go though. 7.5k or 10k may be fine…but I’m NOT going to experiment. We both have oil change monitors on our cars and they both warn us that oil change is due every 5k miles.

IMHO, that is the sane approach and one I follow for most driving. When I refereed and put 20 to 25k miles a year, mostly highway on a car, I would move the change to 7.5k. I move it now to 7.5k during long trip use and during busy times of the year have NO problem extending it then. I have never had a repair related to excessive oil changes intervals. Now, rust, tires, brake jobs etc. that’s where the real money is spent and where the real value and safety of a car is counted in dollars and cents. If we burned propane in our cars, the normal change might be 10k. That would really drive you 3k changers crazy.

Ford is officially at the 7.5k interval as it is with my cars. So even 5k is over maintenance.

What drives the 3k miles mechanics crazy is standing at a service counter and being cursed and threatened with lawsuits by people who now have damaged engines and/or turbochargers from extended oil change intervals.

If everyone wants 7-10k miles intervals then fine but fingers should not be pointed at the mechanics, dealers, or shops when the question arises as to why that new car with only 40k miles on it has a wiped engine due to sludging or coking.
It should be accepted as a fact of life without any disappointment or anger; followed by ponying up on the bill without argument and beginning the process all over again.

I too suggest following the severe service schedule in the owners’ manual. If you exceed that recommendation, you do so at your own risk. Those recommending exceeding that mileage do so at YOUR risk…not theirs.

Honestly, I think doing so more frequently than the owners’ manual severe service recommendation is unnecessary on that car. It doesn’t subject the oil to the high stress conditions that turbocharged or supercharged engines might.

At the same time, I respect OK4450’s experience inside of engines. He’s torn down and rebuilt more engines that most everyone here. He’s seen far more than I have. I’m reluctant to not agree with his 3,000 mile recommendation. At the very lleast, keeping the oil fresher will certainly do no harm.

OK…in the life of a car, the expense of needing an oil change related repair on a modern car in 200k miles that gets oil changes according to the manufacturer, compared to tires, brakes, body etc. repair is practically insignificant. Obviously it has hit home to at least one state, California, who believes that there is little difference and secondly, observed polution level changes are worth doing things right…again. And no, mixed driving anywhere, anytime in the US is NOT severe.

IT’s this notion that the motor is worth more than the other components combined when in reality in modern car it has become one of it’s most reliable component if maintained according to the manual which are going to 7500. Really, having a perpetually change of oil continuously could lead to more reliable motors too. But our pocketbooks and the environment won’t stand for it. A person would be better served sticking to the recommendations but oiling the inner body panels in the rust belt areas as done by a willing garage every year with the money saved. If done right, there is no environmental impact and you have a car worth much more in ten years then the one who has you bragging to the next owner that your rust bucket had 3k oil changes.

I know a shop owner who does all the maintenance on the fleet of a company that does local deliveries. The driving is all stop start, shut down, and restart, about 12 hours every day. They have about 40 vehicles, mostly Chryco minivans and PT cruisers. They have my friend change oil in each one, scheduled at 7000 miles and happening before the 7500 mile mark. Almost all of their vehicles have well over 100K miles, and many have over 300K. At least one Caravan has nearly 400K, and still uses no appreciable oil between changes. Hey, you can’t argue with success.

Car manufacturers also routinely recommend things such as 100k miles + spark plugs changes, valve lash inspections every millenium, and lifetime automatic transmission fluid that never needs to be changed.
Every single one of those recommendations can and do lead to serious problems.

Again, being cursed and threatened by car owners because their engines have bitten the dust at low miles does have an influence on my opinion. Those oil sludge class action suits were filed for a reason, albeit a false one.

Speaking of sludge and Diogenes never finding an honest man, he should have visited Florida. The March 2012 issue of Car Craft (bottom of page 82) has a pic on the Burn Out section of an oil sludged and trashed engine from a van. The owner in this case admits that he got lax on his oil change intervals and voila, that pic was the result. He says he has now learned his lesson and will go back to 3k miles oil change intervals.
At least he’s honest and admitted he was at fault while giving the legitimate reason for his failed motor.

I’ve got 518,500+ miles and still going on a Ford 4 cylinder using 3-5K mile change interval. Didn’t lower the oil on the dipstick between changes until approximately 250-300K on the odometer. Since the car is now using a significant amount of oil and the body and interior are in poor condition I’ve increased the interval to 10K miles, but have also seen quite an increase in oil consumption since I started this at 475K. I decided to see for myself the affects of longer change intervals to make an informed decision about what to do with my better cars. After seeing the affects I’m sold on shorter intervals.

Sorry Fordman…I don’t see your point. Your car was an oil burner before you changed the schedule and will continue to get worse even with the same oil change interval…besides NO ONE is arguing for 10k oil changes ! Moving to 5 to 7.5 would have proven nothing either.

I know BMW has had some problems with engines with their 15k oil change interval recommendation. But that is extreme. Some vehicles like the Toyota V6’s from around 2001 thru 2004 were subject to sludge because the increased temp for pollution control and a poorly designed PVC system. You had to be extremely diligent about changing the oil every 3k miles or use a full synthetic.

From my own personal experience I can say that the 5k oil changes have been fine. Been doing that for years and hundreds of thousands of miles without a problem. But I’m not sure that the 5k oil change is right for every vehicle out there. I’m sure there might be engines where the 3k oil change interval is needed. I have no idea how many engines fall into this category.

As for increased oil changes polluting less. Maybe in some parts of the country…but where I live most of the towns have waste oil burners that put that old oil to good use and saves many towns a lot of money heating their DPW buildings.

Under ideal driving circumstances, with the “right” motor oil and with a perfectly-designed engine, I’m sure that it is possible to go 7,500 miles between oil changes with no consequences. However, that is in an ideal world, which few of us live in–or drive in. Just a glance at the description of “Severe Service” in a mfr’s maintenance schedule should make many people realize that their driving situation is actually in the category of Severe Service, and thus mandates oil changes much more frequently than every 7,500 miles.

Those who argue for 7,500 mile oil change intervals remind me of the folks who brag that they have smoked all of their lives, but that they don’t have lung cancer. Just as not every car subjected to extended oil change intervals is going to fall victim to sludging, not all smokers will develop lung cancer.

However, just as the sight of lung cancer victims dying in agony should dissuade others from smoking, the pictures of engines ruined by sludge deposits should give pause to those who advocate extended oil change intervals. Just the chance of developing problems like this is enough to keep me on my regimen of changing the oil every 4k miles/4 months.

Fordman, I would recommend the same or shorter oil change intervals because there is more blowby, and the grunge that comes with it.

I’ve done 5K miles or 6 months with my last few vehicles, some of which called for 7,500 or 6 months in the Owners Manual.

On cars that don’t get too many miles on them, I change oil twice a year, spring and fall. My mother-in-law had a Pontiac Sunbird (1994) which only accumlated 42,000 miles over a 17 year period. She took it in twice a year and when we finally sold it last year the engine was in near perfect condition.

Dagosa, you’re entitled to your opinion as am I. I know the results I’ve had and that this car has increased oil consumption from a quart every 1200-1500 miles to a quart every 800-1000 miles (approximate increase of 67%) in the past 43.5K miles since going to the longer interval, therefore I opt to stay on the safe side. I’ll continue to change the oil every 3-5K miles on my cars with hopes of exceeding 500K miles on all of them. Since I still have 20+ cases of oil that I bought prior to the increase in oil prices and filters I’ve bought at store closeouts, flea markets and yard sales all for under $1. each, my oil/filter changes are still only costing me about $5. each and 1/2 hour of my time every 3-5K miles, In my opinion this is pretty cheap insurance against engine damage. Just as I pay over $2000. a year for liability insurance on all my vehicles in hopes I’ll never need it. I can’t understand anyone that’s willing to pay $25-$50K for a new car, yet be too cheap to pay $20. for an oil change every 3-5K miles which everyone that’s commented on this thread agree is often enough to insure the engine is being properly lubed. At $20 per oil change the difference in cost of doing an oil change every 5K miles opposed to every 7.5K miles over 75K miles of driving would amount to $100. In 300K miles which is probably more than the life expectancy of the average car this would amount to $400. and approximately 10 hours of the owners time.