The 3,000 Mile Oil Change Myth

[Doc_Bob]

It痴 been a misconception for years that engine oil should be changed every 3000 miles, even though most auto manufacturers now recommend oil changes at 5,000, 7,000, or even 10,000 mile intervals under normal driving conditions.

Greatly improved oils, including synthetic oils, coupled with better engines mean longer spans between oil changes without harming an engine. The 3000 mile interval is a carryover from days when engines used single-grade, non-detergent oils.


Read on......................



The-3-000-Mile-Oil-Change-Myth- Yahoo! Autos Article Page

 

[crabjoe]

I didn't read the article, but I've known about 3000 mile BS for years.

In my diesel pickup, I do oil changes every 10K miles. I came to this number after having my oil analyzed. Even at 10K miles, the oil (dino, NOT synthetic) comes back clean, but it just didn't feel right to go past that.

 

[HarryVanderpool]

Lets see....
So the industry that really needs to move some volume is telling us that we can back off on maintenance of our exsisting fleet?...
Yeah!
Like I'm buying that.

 

[NuBota]

I agree the interval is BS. But I still follow it when the vehicle is under warranty and keep receipts and records.

Had a 2000 Dodge Intrepid with the 2.7L engine. Great car, but developed a serious sludge problem before hitting 40K miles. Timing chain jumped ("hydraulic" tensioner became clogged) but Chrysler argued that the sludge was my fault due to not changing the oil at the prescribed intervals. As I had no records or receipts, I couldn't prove it and they wouldn't fix it under warranty. So now I keep records and change at the recommended interval while under warranty.

Of course it is interesting to see the article is from the environmental folks and not someone just trying to expose a rip-off

 

[irwin]

Careful now, it is true that many engines can handle extended oil changes. It is also true that some can't.

Google VW oil sludge problem and you'll see what I mean, you'll also see it's not just VW.
I've worked in auto repair since the early eighties, had many engines apart, I can tell when oil changes aren't done regularly. This is what I've been told by the owners.."sometimes I let it go 5-6k miles" what I think happens is they let it go 10k miles, I work on their cars enough to know it's not much more.

I recommend 3000 miles oil changes with dyno if there's a lot of stop and go driving, for the the long distance drivers I tell them to follow what's in the manual. Some engines have a large volume of oil like some diesel trucks, depending on situations those engines could go quite a while between changes, but I'd recommend having it tested like crabjoe.

Just a note of caution from someone who has seen dirty oil damage.

 

[dieseldave56]

The problem with extended service policies are not that the oil breaks down but the contaminates that form in the oil . Unburned fuel from cold startups, dilutes oil decreasing the lubricity.Moisture and gycol form as a part of the combustion process ( particularly with the filler ethanol forumlas). That moisture combines with hydrocarbons to form sludge. Sludge is not good , as Mr NuBota can attestify to. Mr NuBota are you South African? Another problem with extended oil service practices is the acid that forms again as part of the combustion process.

So as you can plainly see even OEM filtering ( which generally filters only 10-20 microns, with a full flow filter) will not eliminate the reall problem. I have had Blackstone labs check my fluids in a all my vehicles for a number of years.

I take a number of precausionary steps in my vehicles , as most are collector such as fuel/water seperator filter, remote bye pass filtration systems with <1 micron Fleetguard ES Venturi filters. Also added is a coolant filter . The addition of pre/post lubrication pumps that bring oil pressure to 25-30 psi before startup. These practices I adapted from the diesel engine. I change my fluids myself at the scheduled mileage or time reference as per manufacturer.

Being a retired machinist and hobbist engine builder for 35 years I have noted many changes in engine tolerances and metalurgy due to technology. But I see no practical reason to decrease my maintenance habits.

The 1950 Case DI manual calls for 120 hour of operation before filter and engine oil change. The original engine was rebuilt so now the superior added filtration and grades of oil from todays technology will only extend the life of this machine. Fluid and filter changes are the most inexpensive insurance one can provide their vehicle. I see no advantage in implementing an extended fluid service policy.

 

[dieseldave56]

The problem with extended service policies are not that the oil breaks down but the contaminates that form in the oil . Unburned fuel from cold startups, dilutes oil decreasing the lubricity.Moisture and gycol form as a part of the combustion process ( particularly with the filler ethanol forumlas). That moisture combines with hydrocarbons to form sludge. Sludge is not good , as Mr NuBota can attestify to. Mr NuBota are you South African?

So as you can plainly see even OEM filtering ( which generally filters only 10-20 microns, with a full flow filter) will not eliminate the reall problem. I have had Blackstone labs check my fluids in a all my vehicles for a number of years.

I take a number of precausionary steps in my vehicles , as most are collector such as fuel/water seperator filter, remote bye pass filtration systems with <1 micron Fleetguard ES Venturi filters. Also added is a coolant filter . These practices I adapted from the diesel engine. I change my fluids myself at the scheduled mileage or time reference as per manufacturer.

Being a retired machinist and hobbist engine builder for 35 years I have noted many changes in engine tolerances and metalurgy due to technology. But I see no practical reason to decrease my maintenance habits.

The 1950 Case DI manual calls for 120 hour of operation before filter and engine oil change. The original engine was rebuilt so now the superior added filtration and grades of oil from todays technology will only extend the life of this machine. Fluid and filter changes are the most inexpensive insurance one can provide their vehicle.

 

[JJT]

Based on used oil analysis I do 10kmis oil changes on both cars. Even at 10k the oil analysis says there is life left in the synthetic oil I use, but 10k is a nice easy number to remember. This equates to 2 - 3 oil changes per year. I do use a premium oversized oil filter.

The tractors get an annual change, (under 100 hours each). I'm also running synthetic with the diesels.

I was a 3k oil change guy for 25+ years, (dino not synthetic).

 

[NuBota]

... Mr NuBota are you South African?

No Dave - thought I was being witty - Newbie with a Kubota = NuBota. My whole life no one gets my jokes....

As far as my sludge problem - regular oil changes were done. Problem was the 2.7 engine design. 2000 was it's first year. There were major issues - mainly oil flow that caused the sludge issues. From 2001 on the 2.7 was re-designed to address the issues. However, Chrysler disavowed any problem - AT FIRST. There were enough proven cases - and they finally settled with me - a $4k check to cover replacement motor. Took fours years of many others fighting to get Chrysler to finally pony up - by the time I applied, it was a quick and painless process.

As far as your other points - I have nothing scientific to say. I just know in years past I was horrible about regular maintenance and I would run my vehicles to 150K + miles - even little 4 cyl - with no major engine issues. Designs today seem to be much more sensitive in passenger cars. I believe motor designs to meet EPA standards account for most. Trucks and SUVs seem to be more like the "iron" workhorses of old.

Regardless - I have adopted much stricter maint. habits as I get older - for the sake mentioned before and probably cause I'm becoming an old fart set in his ways.....

 

[ray66v]

I never fell for this, 5k is plenty often for any car driven regularly.

I have done a lot of mostly city driving, (32 years worth), with Pennziol/Fram, My vehicles never use any oil, engines are clean inside when doing maintenance, and always are driven to the junkyard, because everything else is has failed.

Our current inventory; Villager has over 150K, Aerostar, 135K, Malibu 100K. All run like when they were new.

If I had changed my oil every 3K, I would be one of the ones saying, Look at my mileage! it makes a difference!