fishfryer

Maybe I wrote it wrong, sorry for the misunderstanding, but I was talking a bike like my CBR600 that has an oil change every 3k miles will easily make 100K miles without having an oil related problem like bearings or whatever. I know a guy with 200K miles on his CBR600 that just finally got a motor rebuild (and that was due to a crash that cracked part of the motor case.) All he ever did was dino oil every 3k.

The fact that the clutch and tranny use the same oil shows that even with all that crap in suspension (bike oil turns black in no time) a modern car motor can last a very long time due to how good oil is. When you think about it, car oil has it very easy, it doesn't get beat up at 16K RPM and it isn't chewed up in a tranny and it doesn't see worn out clutch material in it like most bikes. I'd bet 500 mile bike oil has more crap in it than 5000 mile car oil.

With my bike, the tranny feels different between oil changes and even using dino vs synthetic. THAT's how I know that oil gets dirty, it slows down your shifting and syncros and stuff.

Saki GT

One thing about motorcycles, they typically have 5-6 quarts of oil despite their small sizes (half liter-1 liter) relative to cars (2-6 liters, 5-6 quarts). Also, motorcycle oil is different than car oil with additives and certain lubrication characteristics - motorcycle oil used in wet clutches can't be too slick or the transmission will slip.

fishfryer

Mine is 3quarts, and again that is for the motor, tranny and clutch. My 3.0 V8 530i had 8 quarts for only the motor, so again I think bikes are WAAAYYYYY harder on oil than cars. Yes, my bike uses low moly oil for the wet clutch, but additives are additives, they are all invented by the same guys and they all work better than we can imagine.

iDomN8U

volume of oil has a big impact to the time frame to switch out the oil.

If you're putting in 8-10 quarts, then you would have almost double the time frame vs 4-5 quarts switch out time frame.

iDomN8U

of course tolerences and other variables impact the change frequency as well

fishfryer

My guess is only moisture build up/burn off and what kind of stuff that makes really affects oil for many tens of thousands of miles, but an engine that is run for very long periods, like in a torture test like a 24 hr race, the oil will hold up fine and whatever breakdown happens, really doesn't matter all that much since oils and metals are so good to begin with.

Steponme

Oil lasts much longer than the filter. The process of changing oil is essentially to change the dirty, worn-out filter. No filter on the market should be used longer than 10K miles, even if BMW suggests 15K.

Slithr

Using synthetic and going about 6k between changes. Agree that a filter change will allow you to go longer.

Mechanic once told me, "I've never seen an engine failure due to clean oil".

WFO Racer

I have a Tundra Crew ,Rav4, Trail Edition 4 Runner at the house. These filters are a pain in the butt to change.

We had a 05 Camry for the nanny to shuttle our boys around. If you farted around it took maybe 15 minutes to change the oil. Canister screw on oil filter ,easy to reach.

The real question is how long do you plan on keeping your vehicle that doing religious oil changes would matter? I keep our cars for 3 years max before I get bored and move on. Key reason I don't buy used.