Why does Oil need to be changed 1 time per year?

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179
Location
Forest Hill MD
Does the oil go bad like radiator coolant? I'm just curious. If I have 20,000 miles/1 year on Amsoil synthetic, why can't I keep going until I hit the 35,000 mile mark? Troy
 
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1,565
Location
palm beach
under ideal curcumstances, the 1 year rule is irrelivant. the only relevant thing to an extended drain is what your oil analisis says. push it 2 years, 5 years whatever, as long as uoa is good the year rule is not applicable. however, if you are not going to to uoa's, than the year rule is somthing to use as this is the "average" i assume for the time an oil turns bad.
 
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3,023
Location
USA-Michigan
So you will buy more oil! The time lime is about as useful as the instructions on most hair shampoo where is says; lather, rinse and repeat. You use more shampoo and they then sell more. But really its more of a disclaimer. If it was not one there, some would go 20 yrs and then say, "you never said I had to change it". Some people will not have any common sense.
 

troy_heagy

Thread starter
Messages
179
Location
Forest Hill MD
quote:
Originally posted by Mike: So you will buy more oil!
Well the time rule makes sense if you drive 5 miles a day. That short trip, cold-engine driving will kill the oil. However, if I drive 100 miles a day/5 days a week then I don't see any reason to change the Amsoil. Even if I did not hit the 35,000 mile limit, I should be able to keep going past one year. (IMHO)
 
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5,785
Location
Dixie
Troy, I've run the same batch of Amsoil for two full years on several occasions and it tested out fine after 15k-21k miles. This was done under primarily highway driving conditions with a good running engine .... I would normally recommend testing the oil after a year if you are going to do this, however. TooSlick
 
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3,683
Location
Chattanooga, TN
The assumption may be that if you have not put enough miles on the oil to warrant a change in a year it is probably contaminated with condensation, fuel etc. due to the short trips or non usage. On one of my cars I purchased the previous owner had Mobil 1 in the crankcase for 18 months, about 3000 miles. Oil analyzed out fine so it depends on a lot of factors, especially heating it up once you start it.
 

Patman

Staff member
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21,989
Location
Oakville, Ontario
I think it also depends on the size of the cooling system in the car too. With a small engine that has a small cooling system, it gets up to operating temperature much faster, which means it also heats up the oil faster too. So under those conditions, it could handle infrequent driving/short trips much better than a car which takes twice as long to heat up the oil.
 

troy_heagy

Thread starter
Messages
179
Location
Forest Hill MD
I like those elderly folks with low-mileage cars. My mom just sold her 1987 Plymouth to me for only $1000. Mile: 25,000! It's practically a new car! . So the only fluid I *have* to change on time basis is my radiator coolant: Once every 2 years. Correct? Troy
 
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3,023
Location
USA-Michigan
The quick lube places put stickers in the windows, every 3000 miles or 3 months. So if you only drove 2000 miles a year, you would have to change the oil 4x in one year enriching them and saving you nothing. I know of someone who is hooked on this. The trouble is she will never put enough miles on the car to ever have any engine problems but these quick lube places put that sticker in your face. Kind of tee's me off that they take advantage of elderly folks like that. I have tried to convince her to go yearly but it causes more problems, they have her worried about her car. She only drives about 2000 miles a year. Her last car being a 1986 Pontiac 6000 on had 39,000 miles when we sold it to get here a new Lumina in 2000, only a little over 5,000 on it now. [ May 27, 2003, 12:21 PM: Message edited by: Mike ]
 

Patman

Staff member
Messages
21,989
Location
Oakville, Ontario
quote:
Originally posted by troy_heagy: I like those elderly folks with low-mileage cars. My mom just sold her 1987 Plymouth to me for only $1000. Mile: 25,000! It's practically a new car!
A guy at work bought a 1986 Pontiac Grand Prix for $500 with just 22k on it! An elderly guy owned it.
 
Messages
191
Location
KY
quote:
Originally posted by troy_heagy: [QB]So the only fluid I *have* to change on time basis is my radiator coolant: Once every 2 years. [QB]
Most manufacturers recommend changing the brake fluid every 2 years. The coolant schedule may be different for different makes of vehicles. Conventional coolant is replaced every 2 years; "long-life" coolant every 3-5 (Ford is 3 years/50,000 miles, GM is 5 years/150,000 miles), and some European brands utilize lifetime coolant.
 
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3,023
Location
USA-Michigan
Changing the brake fluid every 2 yrs? I never heard of that. I just went thru a GM service manual and no mention of that at all. Even for replacing the rotors its say to drain about 2/3 of the fluid from the master cylinder but it make not mention of changing the brake fluid. Brake fluid will last indefinitely if not contaminated with moisture.
 
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1,565
Location
palm beach
mike, the problem is that brake fluid is awalys exposed to moisture rich air. your master cylinder resivor has a cap in which there is a vent hole. this hole continously sucks in and pushes out air while you pump your brakes.
 
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3,023
Location
USA-Michigan
What kind of vehicle are you talking about with a vent hole in the M/C?. I just looked over my 4 GM vehicles (92,93, 01 & 02) and if there is no vent, there is a air tight rubber seal. I spoke to a ASE (20+ yrs experience) brake man this AM (my 92 K1500 needs new rotors etc) and he shook his head when I told him some were advocating changing brake fluid every 2 yrs. No need to change brake fluid unless there is contamination present. [ May 29, 2003, 10:53 AM: Message edited by: Mike ]
 
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7,775
Location
Oklahoma
[QUOTE]Originally posted by troy_heagy: [QB] Does the oil go bad like radiator coolant? Radiator fluid go bad? I know the BOOK says to change it but it's just water and glycol. What would go bad??? Lot of the newer cars, as mentioned in an earlier reply, don't even mention changing radiator fluids. Anybody??
 

Patman

Staff member
Messages
21,989
Location
Oakville, Ontario
quote:
Originally posted by Mike: What kind of vehicle are you talking about with a vent hole in the M/C?. I just looked over my 4 GM vehicles (92,93, 01 & 02) and if there is no vent, there is a air tight rubber seal. I spoke to a ASE (20+ yrs experience) brake man this AM (my 92 K1500 needs new rotors etc) and he shook his head when I told him some were advocating changing brake fluid every 2 yrs. No need to change brake fluid unless there is contamination present.
There are a lot of guys in my car club that are into autocrossing and road racing, and every single one of them recommends changing out the brake fluid every year. Even on a normal street driven car they say it should be done every 2-3 years. I noticed better braking on my 97 GTP when I had it's brake fluid flushed (this was in early 2001, so the fluid was at least 4 years old)
 
Messages
3,683
Location
Chattanooga, TN
quote:
Originally posted by Schmoe: [QUOTE]Originally posted by troy_heagy: [QB] Radiator fluid go bad? I know the BOOK says to change it but it's just water and glycol. What would go bad??? Lot of the newer cars, as mentioned in an earlier reply, don't even mention changing radiator fluids. Anybody??
Coolant is composed of additives as well to protect the engine. Yes, coolant needs to be changed. For the old ethelene glyco green stuff about every two eyars after the first change and for the dexcool, well they say 100,000 miles or 5 years but I woould opt for three to plkay it safe. Amazing how much crap drains out of the radiators after 3 years.
 

mph

Messages
356
Location
Johnstown, PA
quote:
Originally posted by Mike: Changing the brake fluid every 2 yrs? I never heard of that.
It's definitely a scheduled item for my Honda. I think it's on 2 year/30,000 mile schedule, but I'm not positive. When I changed my brake fluid last year, I don't know how long the old stuff had been in there. At least since I bought the car used three years before. The fluid was dark, slimy, and viscous, not at all like the new fluid. I don't know for sure that the transformation would affect performance, but it was obvious that it wasn't the same as new fluid.
 
Messages
372
Location
Rancho Cucamonga, CA
Yeah, I have an '03 Accord and Honda recommends changing the brake fluid every 2 or 3 years (can't remember which) regardless of miles. They are probably playing it safe. Just a little bit of air or moisture contaminant will have an affect on braking performance. Spongy brakes are often attributed to air in the lines. I think the guy above who said only to change if contaminated had it right. Sometimes it's easier to just change it then to determine whether or not it is contaminated. Honda decided 2-3 years is a good interval. Regarding coolant, there can be dirt and other contaminants introduced from the resevoir through the overflow hose, and also deposits from inside the engine/radiator that fleck off and float around in there. I've heard anywhere from once a year to every 100,000 miles (my Honda). It's easy to do and not expensive, so I generally flush my coolant once a year.
 
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