I own a 2004 Jeep Grand Cherokee with 83K miles on it. I’ve been using regular motor oil at every 3K oil change. Do you think it’s time for me to switch to the ‘high mileage’ motor oil and in either case of yes or no kindly tell me why…thanks.
High mileage oils are used when there’s an issue with oil consumption. Such as leaking seals or leaking rings. If the vehicle doesn’t display these issues there’s no reason to use a high mileage oil.
Tester
I would wait until it has at least 150,000 miles for something like that. 30 years ago, it was rare for a car to reach 100,000 miles with no major problems. Today, the same goes for 200,000 miles with most cars.
Thanks a lot both of you (Tester and Whitey). Guess what? even after telling the guy not to use the high mileage oil this morning he still did. What should I do, get it drained out ASAP and put the regular oil in or wait for 3K (next service) for the regular one?
Leave it in. As long as it’s the correct viscocity, it won’t hurt anything.
There’s really nothing wrong with leaving the high mileage version in the motor. Basically, it has some additives to help older motors run longer. Typically:
- Extra anti-wear additive to help protect critical engine parts.
- Reduce the sludge and deposits that can build up.
- Contain special seal conditioners to help recondition seals and prevent leaks.
Of course, every oil is different, and (most) synthetics will perform better than conventional over time - they also cost more.
There’s no magic “switch at xxx miles” formula. It all depends on your engine, and how it’s been treated. It’s a decision to be made by you and your mechanic. If you don’t have any issues (re Tester’s post), there’s no reason to change, but there’s no harm in leaving that fill there for a few thousand.
The older tolerance specifications that were used when engines were made had quite a bit of play in them. Not so with today’s engines. The tolerances are very tight, and getting better all the time. That’s why it’s getting so common to have very high mileages cars. Not sure if you’ve ever heard “My Toyota just hit 100K…it’s just about broken in.” They’re all machined and put together by computers now - which is also why the 10 year/100,000 mile power-train warranty is fast becoming a standard. They’re just that sure of the manufacturing processes now…not to mention competition for us…the ones who buy them. 
Good luck!
Chase
The concept is called “Shelf Space”…The more I have, the less you have…
I’ve yet to use it…even with vehicles well past 300k miles…and NEVER had an issue.
Don’t confuse “High Mileage” with “Extended Drain Interval” oils. As pointed out, high mileage has additonal additives to fight oil leaks and consumption, while extended drain oils have much more of the normal additives, allowing a longer time between changes. Many European cars require this type of oil, which is very expensive.
In any case, your 3000 mile drain interval can easily be lengthened if you do mainly highway driving. Most cars now have 4000-5000 drain itervals in their manuals. If your driving is “severe service” (many short trips) the 3000 miles interval is just right, and just continue what you are doing now.