View Full Version : Oil change myths
85_SS_302_Coupe
04-19-2010, 08:44 PM
Someone shed some light on this topic for me because every time my buddy says this i wanna punch him in the face:
"oh i changed my oil BEFORE i put it in storage so it should be ok when i bring it out"
Ok....WTF is the logic behind changing your oil and parking your car? So you pour new oil in and leave it sitting in the oil pan over winter...exactly HOW is this protecting your engine any better than having 20k mile oil sitting in the oil pan? Until the engine is running, it doesn't F'in matter if there's NO oil in the pan! Or am i totally wrong on this? Seems to me like it's a huge waste of money because technically you're supposed to change the oil 3k or 3 months, so by the time he pulls it out of storage in the spring his oil is old enough to be changed. Wouldn't it make more sense to leave the old oil in and change it right before you pull it out of storage? Seems like you're wasting an oil change for nothing.
Or am i completely wrong and there's some magical benefit of having new oil sitting in the oil pan not getting circulated through the engine? :confused:
Mustard
04-19-2010, 09:02 PM
to be honest I would like to know this as well
Brandon Alsept
04-19-2010, 09:28 PM
Unless you have a climate controlled garage it is useless to change your oil and then park it for a few months. As it will need changed before you run it anyways. As the engine gets cold and warms up it builds up a decent amount of condensation in the engine and drips into the oil. Now a bunch of those cycles can end in a decent amount of water in your oil. I mean it always happens but normal driving can burn off the small amount of water that forms say overnight or a week.
In the grand scheme of it all a oil change is very very cheap protection of your investment.:bigthumb
85_SS_302_Coupe
04-19-2010, 09:39 PM
Right so am i on the right page here? It's smarter to just leave your old oil in, park it, and change the oil right before the first time you start it up to bring it out of storage. Right? Otherwise your oil is just sitting in the pan...i don't see how it would make any difference.
331TwistedWedge
04-19-2010, 09:51 PM
my question is.......i know oil is supposed to be changed every 3k miles, but why after 3 months? ... is it like milk and has an expiration date? ... it takes me 5 years to put 3k miles on the coupe, so i change it once a year ... beginning of the race season for the few times that i do run ...
85_SS_302_Coupe
04-19-2010, 09:52 PM
I've never heard a good explanation on the 3 month thing. Also everything i've read says the 3k mile thing is really just a safe bet and that most modern oils can go much longer without changing it. Of course, i think performance cars are a different breed. I'm with you...it takes a me all summer to put 3k on my car so i just try to change it once a year minimum.
Squale iii
04-19-2010, 10:13 PM
my question is.......i know oil is supposed to be changed every 3k miles, but why after 3 months? ... is it like milk and has an expiration date? ... it takes me 5 years to put 3k miles on the coupe, so i change it once a year ... beginning of the race season for the few times that i do run ...
3 months is probably the average time it takes a commuter to put 3k miles on a car. That's why they say 3 months OR 3k miles. If you drive more often than the national average, yours would be more often. You also need to consider how hard you're driving your car. I know 3k miles on my camaro are probably harder than the 3k miles I put on our Cabrio. So if you're out drag racing, it should probably be changed more often than the average car.
Clean91lx
04-19-2010, 10:27 PM
I would tend to agree with the fact that, "You change the oil just before you take it out" of storage. Another fact...my dad was a stickler on changing oil. We have work trucks with over 250,000 miles on them that still run (not great) BUT never-the-less they run still. My dad changes the oil in every truck EVERY 2,000 miles (we pull trailers and are on dusty job site conditions). He took a truck in that had to be re-paired...head gasket because the person let it overheat...this truck had over 250,000 miles on it (CHEVY) and the mechanic said it was the cleanest looking set of valves he had ever seen....
I am NOT a CHEVY GUY AT ALL, BUT I think it comes down to changing the oil and preventative maintenance AS WELL.
cobrajoe
04-20-2010, 04:57 AM
motorkote!:lol:
Pitbull1052
04-20-2010, 09:38 AM
I use to work for a pretty large dealer here in Cincy and we use to have the quaker state guy come in all the time, they'd buy our old oil and what not. Now I'm just repeating what he said and he was a chemical engineer, I think there is atleast one other chemical engineer on here so he can pipe in too....... but anyway he stated that oil doesnt go bad or doesnt loose it's viscosity like the commercials always say and that really you don't have to do the 3k mile thing unless you're using cheap filters that's what goes bad they loose their ability to filter. Again just what he said.......
84stang
04-20-2010, 10:01 AM
I tend to agree with the before and after theory. Here is the reasoning but I might be wrong.
Old oil is dirty and full of contaminants. These contaminants that are suspended in the old could settle and harden causing a coating of crap in the oil pan and inside the pickup tube.
This coating of crap may or may not come out after storage during the oil change. If not then the engine will suck it up into the pump and filter upon restarting the engine.
If you want to protect your investment by spending 15 bucks on a cheap oil change before and after storage I think it is a good idea.
Again I am not a chemical engineer but I am of the better safe than sorry crowd.
facemelter71
04-20-2010, 10:55 AM
Oil has an additive packet added to it before you buy it.I dont know the makeup of these additives to the oil.These special chemicals they add wear out and it loses it lubricity after roughly 3 months.They account for weather changes and everything since this directly effects oil.Synthetic oil is different,since it has a different chemical makeup.Thats how they came out with longer mileage oil.They have made some of the chemicals they add to last longer than with regular conventional motor oil.
Also changing your oil before letting a vehicle sit is not a bad idea.Since some of the blowby and condensation you get mixes with the oil and some of the by-product of this chemical reaction with oil becomes corrosive when it sits for awhile.So oil with 3500 miles on it will have more of this "crap" than say oil with 1500 miles on it.
More in a minute.
Katmandu
04-20-2010, 12:02 PM
he was a chemical engineer, I think there is atleast one other chemical engineer on here so he can pipe in too....... but anyway he stated that oil doesnt go bad or doesnt loose it's viscosity like the commercials always say and that really you don't have to do the 3k mile thing unless you're using cheap filters that's what goes bad they loose their ability to filter. Again just what he said.......That is true.
Many oil change places now used "Recycled" or "Remanufactured" oil.
The molecules in the oil do not breakdown. The oil does get contaminated with dirt, soot etc... They're now "cleaning" the used oil and replacing the additives and reusing it.
Bottom line with oil changes is to follow your vehicles owner's manual.
A lot of oil change places push the 3,000/3 month thing as a marketing ploy to get more business.
If you don't drive under Severe Conditions and you change your oil every 3,000 miles/3 months (or less) you're only making the Oil Companies RICHER!
.
Pitbull1052
04-20-2010, 12:04 PM
That is true.
Many oil change places now used "Recycled" or "Remanufactured" oil.
The molecules in the oil do not breakdown. The oil does get contaminated with dirt, soot etc... They're now "cleaning" the used oil and replacing the additives and reusing it.
Bottom line with oil changes is to follow your vehicles owner's manual.
A lot of oil change places push the 3,000/3 month thing as a marketing ploy to get more business.
awesome I always thought it sounded like some good bs ya know but never really validated it.......
Katmandu
04-20-2010, 12:14 PM
awesome I always thought it sounded like some good bs ya know but never really validated it.......Exactly.
I change the oil in my BMW 530i only twice a year. Maybe every 6-7,000 miles.
But it's on the highway about 99% of the time so it's easy miles. Even though I can't drive 55! (Or 65 either!) :D
Pitbull1052
04-20-2010, 12:20 PM
I do mine about three times a year I guess and I only really drive it from Amelia to downtown and back. But I typically run Royal Purple
Foxxx5oh
04-20-2010, 12:24 PM
oil changes are all really dependent on how you drive, when i had my diesel, regardless of whether i drove it 10 miles or 10000 miles, it got an oil change every couple months. now that truck saw a lot of abuse and usually burned/leaked almost a gallon of oil between changes anyway, but my dad on the other hand, changes his once a year in his PSD with no problems. but with the Bronco, i use synthetic blend motorcraft with an FL-1A filter, and usually change the oil about every 5-6000 miles since it sees a lot of distance driving.
OH!! and friendly tip from an Autozone employee, Motorcraft oil and filters are on sale now, you can get the 5+ quart jug and a motorcraft filter for 17.99 :)
Foxxx5oh
04-20-2010, 12:25 PM
I do mine about three times a year I guess and I only really drive it from Amelia to downtown and back. But I typically run Royal Purple
i ran royal purple in my 84 SVO and it saw an oil change every 3 months because of the amount that it sat when it wasnt getting driven especially when it was cold an snowy.
Pitbull1052
04-20-2010, 01:02 PM
i ran royal purple in my 84 SVO and it saw an oil change every 3 months because of the amount that it sat when it wasnt getting driven especially when it was cold an snowy.
understandable.... mine's driven every day
85_SS_302_Coupe
04-20-2010, 04:26 PM
I could except the sludge settling in the pan and possibly hardening idea....but only if your car hasn't had routine oil changes in the first place to make that sludge build up. Otherwise i think anything suspended in the oil is going to settle over night or over the week if your car is a weekend toy. If that's the case then we should be changing our oil every weekend before we take our cars out.
I've also hard about oil not breaking down like they say it does...There's an old mag article that talked a little about this in one of the editors drag cars...he said he never changes the oil...just changes the filter and tops off the oil and it's always clean looking on the dip stick.
Foxxx5oh
04-20-2010, 05:08 PM
I've also hard about oil not breaking down like they say it does...There's an old mag article that talked a little about this in one of the editors drag cars...he said he never changes the oil...just changes the filter and tops off the oil and it's always clean looking on the dip stick.
ive seen that first hand, guy had a late 70's camaro that he just rebuilt, but he changed the filter every couple months or so and topped it off, and he did one complete oil change on his car a year right before the season opened
Mista Bone
04-21-2010, 12:55 AM
Mobil 5000 is my preferred oil with STP/Purolater filters.
My courier car that sees 700 miles a week, I change it every 7-8k miles, auto tranny fluid every 15k miles which is KEY to making a Honda slushbox last.
The back up car, every 5k miles. The "toy car CRX, every 3k miles as it doesn't get driven much.
The old 3k/3 months was before oil was improved. Pennzoil Platinum can easily go 10k miles on a decent running car that doesn't have a lot of blow by.
Mista Bone
04-21-2010, 01:01 AM
I've also hard about oil not breaking down like they say it does...There's an old mag article that talked a little about this in one of the editors drag cars...he said he never changes the oil...just changes the filter and tops off the oil and it's always clean looking on the dip stick.
Dirty oil is good oil doing it's job. The carbon from combustion blow by is being suspended in the oil. The carbon is too small to be caught by the filter.
Also a car that "doesn't use a drop of oil" is a BAD thing. Engines consume small amounts oil, PERIOD. If your engine isn't using oil judging by the dipstick, something is making up for used oil.
Motor oil does break down, aka shear. Synthetic oil just has longer chains to break down.
BITOG
http://www.bobistheoilguy.com/cms/
LOTS of good reading there.
331TwistedWedge
04-21-2010, 01:16 AM
i have 335,000 plus miles on my 88 nissan pickup ... i change it about every 6 months or 7000-8000 miles ... been doing that for the past 3-4 years with valvoline maxlife ... so i believe oil doesn't go bad, i guess it just gets a bit dirty ...
chad393na
04-21-2010, 01:16 AM
The 3 months thing is because ideally if you don't put 3k miles in three months, you are making mostly short trips. Short trips is what tends to make oil dirty because the engine doesn't run long enough/get hot enough to burn off the moisture. Now if the car isn't being driven at all in those three months, I don't see the point in changing it then.
inferno50
04-21-2010, 01:36 AM
the mustang gets 10w30 penzoil every 3000, escape gets motorcraft 5w20semi every 5,000, cavalier gets whatever is cheap and i have only done it 3 times in 100,000 miles and it does a really good but funny burnout that will smoke them through fourth gear. i have done it an easy 100 times,it is the indestructable car. beat that bitches. Wait to see it in the figure eight race at the clermont county fair this year, it will be the one with my ex wifes car written on the side. lol. seriously.
Mista Bone
04-21-2010, 01:41 AM
The 3 months thing is because ideally if you don't put 3k miles in three months, you are making mostly short trips. Short trips is what tends to make oil dirty because the engine doesn't run long enough/get hot enough to burn off the moisture. Now if the car isn't being driven at all in those three months, I don't see the point in changing it then.
I agree.
Short trips and shitty oil.....
http://i107.photobucket.com/albums/m307/bonespec/Honda/D15Baby8/Part%201/P5220016.jpg
150k miles on Exxon Superflo 5w30 which is now Mobil 5000.....
http://i107.photobucket.com/albums/m307/bonespec/Honda/D16Z6/camchange1.jpg
http://i107.photobucket.com/albums/m307/bonespec/Honda/D16Z6/camchange2.jpg
http://i107.photobucket.com/albums/m307/bonespec/Honda/D16Z6/Zexy1.jpg
4n_eatr
04-22-2010, 10:02 PM
I was taught in GM's ASEP school that Oil can actually START to deteriorate after approx 6 months, so they say 3 months just to perform good preventative maintenance . That's GM's take on it from one my manuals they gave me.
Black Horse
04-22-2010, 11:01 PM
Here is what I was taught:
Leaving oil in a car for an extended period of time is not a good thing. The contaiminates and acids (unburnt gas, and a list of chemicals) actuallly eats away at your internals, bearings, seals etc.
A fresh oil change will keep this from happening. The only drawback is that consensation forms and can leave moisture in the oil (on the bottom since it is heavier than oil).
With all this being said - change it before you store it, drain any water out of the pan before you fire it up after its been stored or just change the oil once again. Cheap insurance.
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