Oil life?? Time vs. mileage ....

-
SleeperScamp

SleeperScamp

Well-Known Member
Joined
May 8, 2006
Messages
2,081
Reaction score
58
Location
Texas
So if it takes two years to put 3000 miles on your car should the oil be good???
 
That's a good question. The oil companies would have you believe 3,000 miles or 3 months. Personally I believe you could double those numbers, as long as you have a good filter, don't overheat the car, etc.

20/20 tv series did an episode on this very thing, using NewYork taxicabs as the control group; over a period of a year. They found NO measure able difference in 3,000 mile oil changes vs 7,000 mile intervals
 
with fuel injection and very precise fuel metering oil change intervals have been bumped up quite abit, but a carburetor that has little tuning I would use the 3000 Mile rule

as far as time goes change it every year, oil that sits in the car for storage will accumulate moisture and should be changed in the spring before startup
 
I agree with bighammer, EXCEPT that you specifically gave a very low amount of miles in a long period. Not being driven that much gives moisture and contaminants a chance to take a foothold on your oil. Being driven on a regular basis up to operating temperature is what makes oil last. The proper operating temperature is a must to help boil out all of the contamination that gets into oil. The less you drive it, the more you should change the oil. That's just my opinion and I am stickin with it.
 
The reason they say three months is the additive package in oil starts to break down. The actual oil wouldn't break down it will last for ever. It's all the additives that the gov't wants in the oil.
 
I don't know.......the 3K mile crapola came about when the quick lube places starting popping up. All of the manufacturers owners manuals have similar specs for oil changes. Ford for example says 7500 miles for regular service and 5K miles for "severe service". They all have similar suggestions.
 
Well most every time I drive my car it's to a cruise in 30 minutes to an hour away from my house so the engine is usually ran at full temperature for some time.. The oil always looks clean ( probably means nothing).. Think I'll just change it every spring for cheap insurance... Thanks for the input...
 
I think the big thing is moisture and combustion contaminants. If you could afford to pay for periodic analysis, you could probably prolong it. But it's undoubtedly cheaper just to change it.

Because I drive so little anymore, I think nothing of letting my oil go 2 years at a time, but no longer than that. My 95 Olds, which belonged to my Mom, still to this day only has less than 50K. That's right......50K. Before my legs got so damn bad, I rode by trike all over hell in this town. I may put "More battery" in it and ride it some more, LOL

4566750741_bce2186a6c.jpg


attachment.php
 
I change my oil in my classics when I get them out after the winter. I put less than 3000 a year on them. The newer cars with fuel injection and overdrive are a different game. First, fuel injection runs cleaner. Second, the overdrive takes about 500 rpms off every minute of highway speeds. That is 30,000 less revolutions every hour, or approximately every 60 miles. Now picture the revolutions overdrive saves in a few thousand miles?! I change my oil in my FI overdrive vehicles every 5000 miles. This happens in approx. 3-4 months
 
As long as the oil doesn't have any moisture in it (looks Milky) and hasn't turned to dark brown or black it is still good.


Never had Mobil-1 ever show any signs of moisture no matter how long it stays in the engine.

As far as additives go , they don't deteriorate over time , they deteriorate from being used or from contaminates.

Modern oil is a lot more durable .

I change the oil in my hot rod when it just starts to turn from yellow to light brown no matter how many miles are on it.

Now my daily drivers get changed at 5k with mobil-1 or 3k with conventional oil or earlier it the oil has turned black on the stick
 
I've heard this question several times before, only in a different manner..
"If motor oil can remain fresh while sitting in the bottle on a shelf indefinitely, how does it not last once poured into a engine ?".
Answer is A clean, sealed, container, versus environmental contamination.
We cant get 100% of the old dirty oil out or close the crack case air tight.
 
Some of y'all have hilarious reasons to change your oil at different intervals, the point is, change it because you can, it's cheap insurance.
 
PoisonDart74 said:
Some of y'all have hilarious reasons to change your oil at different intervals, the point is, change it because you can, it's cheap insurance.
Click to expand...


I could brush my teeth 10 times a day too , to help prevent cavities because it's cheap insurance.
Or I could use some common sense from 35+ years of doing automotive work and only do the job when needed.
 
Any more it is not cheap insurance. Jiffy lube, cheap yes! But crappy oil with low dollar filter. Mobile 1 is not cheap by any standards. 2001 Dakota R/T I bought new and still drive. Changed intake manifold and was blown away inside of engine was brown. (58000 miles) No sludge, but my point is every person here is consistent with contaminents after oil is poured in. I compromise with 4000 mile oil changes and it is still working good so far. My 2 cents, I think there is a ton of good advice here. Thanks to all with sharing!
 
3,000 miles or 6 months, which ever occurs first is the general rule....especially if the drive is 30 minutes or less each time.
It takes 20 minutes at operating temp for the engine to start getting rid of the condensation of the night before, and the combustion stuff from the day before from the oil.
If the daily drive is more like 1 hour or more, then it can be stretched out to 6,000 mile intervals.....but still 6 months.
 
same goes for other fluids. I've seen people that change their oil every 2500 miles but never once have the coolant changed, or transmission fluid changed, or differentials serviced. and the big one that nobody does is changing brake fluid.
it should be changed once a year or every 2 years at most. it will absorb and hold water and damage calipers/brake cylinders / lines from the inside out.

they have some red/blue stuff you can use when doing a brake fluid change, you can bleed the whole system out and when it changes color you know you got it all.

engine oil, that's cheap to get a change. 50 bucks or so and worth it once a year on a car you don't drive constantly.
 
I run mobile 1 full synthetic the advanced formula (not sure the specific name at the moment but its the most expensive they have). I've had it in my 08 titan for 12k miles and it still looks fairly new. That is higher then I would normally go but right when I was going to change it we got that cold spell so I just let it go.
 
In the 80's I worked on Mack trucks. Oil change(per Mack) was 25,000 miles.BUT they had 3 filters and held 56 quarts of oil.Useless info but just thought about it so I thru it in..:blob:
 
my daily drivers get done at about 5000 miles. basically whatever the owners manual says. the 3000 mile oil change is just a money grab scheme especially these days and how much better the oil is.

my classic cars i do every spring no matter what the mileage is. i figure after sitting all winter there has to be condensate and all in it.
 
I have spent most of my life working in the oil industry and i must say i agree with all of you , everyone that posted comments here is right in one way or another. The main reason that we have 7500 mile oil intervals is purely dollars and cents , its all about making the yearly maint expense as cheap as possible . In many cases they can get away with the 7500 interval and in the cases they cant the OEM has considered the warranty repair an expense of doing business. Compared to 5 yrs ago the additive package in oil today is very sensitive and like one person mentioned its not will the oil wear out its how much dirt and moistue it absorbs. There many good additives you can use that are designed to treat the matal not the oil ( Justice brothers 23P,BG 44MOA,Z Max) these products use the oil as carrier and treat the lubricated surfaces of your engine so if the oil loses its lubricity the damage will be avoided . If you run a Holley or edelbrock carb , or really a card in general your oil breaks down quickly due to fuel contamination . in our old muscle cars oil break down is excellerated by heat that is created by our need to constantly excellerate , after all thats what our car were made to do . One other topic i would also mention is synthetic oil in a musle car , in a car with a carb , due to contamination synthetic is a waste of money , it will be diluted with fuel and dirt long before its advertised 7500 to 10,000 mileage life . Myself i change the oil in all of my own cars and trucks every 2500 miles, its cheap insurance for an expensive piece of machinery, many will think im crazy but i have found this formula has given me nearly maint free cars and truck for a long time .You wonna remember the manufacturer does not have in you in mind when making recommendations, they want you to buy a new car . So a longf lasting car does not fit into the big picture . As far as oil being better then then it ever has , i could not disagree more with that mind set. The new additive packages they oil companys are using are very fragile and often make oil worse not better .
 
.You wonna remember the manufacturer does not have in you in mind when making recommendations, they want you to buy a new car
Click to expand...


i don't know. my last car had 180,000 miles on it when i sold it. still ran like a top. the girl i sold it to drove it like 5 more years before trading it in. changed the oil where the owners manual said.

i could not disagree more with that mind set. The new additive packages they oil companys are using are very fragile and often make oil worse not better .
Click to expand...

i don't see the gunk up with the newer oils that you did with the stuff from say 1970.
 
My Neon's oil is at least a year old. I think it's had 6 oil changes over 13 years and 200K+ miles. My truck's is 2-3 years old but if it's got 1000 miles on it I'd be surprised.

I think oil takes a long time to get "sour". If it's just sitting it's getting condensation in the engine but not mixing with the oil. It will get mixed when you fire it cold, and it will boil out of it when it reaches operating temp. This happens in minute levels every day. Leave it sitting outside for a year or two and you'll have some water in the bottom of the pan. It took 10 years but I have enough water in a 400 to push the oil out the dip stick tube hole of the block.
 
You must log in or register to reply here.
-

Back
Top