We’re anonymous here, so we’ll call the characters in this true story “Dad” and “Sonny.” Dad doesn’t believe in oil changes, so Sonny “borrowed” the truck one day and got us a sample. Sonny told his dad the truck was leaking oil in his driveway while he was unloading stuff from Home Depot (it wasn’t), so while he had it he “fixed” the leak and changed the oil. Dad grumbled and said he should have left it alone, but agreed it was time.
This is factory oil in Dad’s 1997 Nissan pickup truck with 122,635 miles on it. And you know, for an oil that’s been in place as long as this one has, the oil doesn’t look half bad. It was thick, like a 15W/40. Fuel was present, though without trends we don’t know if that’s a temporary thing or if it’s always present. Bearing wear (copper, lead, and tin) is heavy, as is upper-end wear (aluminum and iron), but the rings (chrome) are wearing well. Sonny says the engine starts easier now and it isn’t as labored as it was when it runs.
We’re not sure if these results are a testament to Nissan’s engineering or Dad’s good driving, but either way, next time you get worried that it’s been six months since you changed your oil, you can remember Sonny and Dad and breathe a little easier!
Like I've pointed out in all these oil threads people sweat too much change intervals and being one viscocity weight out by 'mistake' and freak out like they should change their oil
Engines are a lot more reliable than people give them credit for and while I'd never go 122k miles LOL
Those 3k changes are insane because its not cheap 'insurance' and a engine will fail because of defect not the oil you use 'in spec and changed based on driving style'
I've had 4 cars go between 180K and 220K before I got rid of them , never did an oil change less than 6k miles and engine problems weren't on the radar as far as what was wrong with them, mostly just age 12+ yrs and all were drivable and went on as beater cars to somebody, I know 2 are still on the road
Labortories
How would you know it was factory oil if it's been getting topped up over the last 15 years? Seems like there'd be no sign left of the factory oil.
I don't know about a lab report that can't spell it's own name...
When I worked for Toyota (@1996-97) we had a V6 4-Runner come in with a knock complaint. It had just over 60K miles, and the oil had never been changed as far as we could tell. The oil in the pan was as thick as chocolate pudding, and the bearings were shot top to bottom.
If the story about the Nissan is true, the oil is more impressive than the engine.
This post ignores many details..
Depending on the engine, viscosity can be incredibly important. On the bmw s54 (specced for 10w-60) putting in 5w-30 will just about guarantee rod bearing issues.
Yep, with the Ford Modular motors, especially the later model (04+) 5.4s, one weight off can, and will, kill the cams between oil changes.
However, on my truck, I've gone over 3k miles on the oil since I last changed it, and the oil still looks new.
Sounds more like a metallurgy or design flaw than any sound engineering reason to be THAT sensitive to oil weight. Even the same weight oil between manufacturers can range the extremes of the scale for a given weight.