No oil change at all. How long will it last?

[Kuato]

Back in the 90's a friend of mine worked at a gas station. One day a mom in a Ford Taurus wagon (kids included) pulled in and filled up. Then she tried to start it but it wouldn't turn over. She asked him for help and in the course of asking her questions he found that she didn't know that the oil was supposed to be changed, but she had at least checked it and kept it filled. She ended up needing a new engine - at just over 60k miles on the clock.

 

[Spazdog]

I had a client that worked for a pilot-car service for oversize loads.

Every month she came in her Freestyle's OLM read to CHANGE OIL. She said she did not want to get the oil changed because she had a breathalyzer in her car. (the Judge apparently allowed her to keep her DOT pilot/escort car certification with an IID installed)

Anyway, she figures about 5-6000 miles a month on average...sometimes more. Over the course of two years that amounts to a minimum of 120,000 miles.

Her engine was noisy when I removed the Breathalyzer, but it still ran.

 

[benjy]

old i see but in the 70's pennzoil was poop!!! got an engine in a friends shop for a rebuild + i did the teardown getting it ready for the "hot-tank" a heated chemical solution that cleaned to bare metal. i filled a pound coffee can with SLUDGE + when the owner stopped in i asked him. you run pennzoil + he asked how did you know!!!! its surely better today as most oils are.

 

[EMPIRE]

Same oil, and w/o changing the filter?
I suspect it all depends on how much oil is used at each top-off, etc.

Engine fail comes from when the oil shears allowing metal-metal contact. If the motor itself operates well below oil shearing levels, the oil can protect almost indefinitely (in terms of lubrication). Anti corrosion is the other aspect to longevity. Dino oils in wet places likes to suck in water.

 

[OilReport99]

Any stories about how many miles an engine will last when the original fill was never changed?

Or an oil change was left in till the engine quit for good. Dino or synthetic?

That would make an awesome Project Farm "test". Why don't you give him a call?