Oil change frequency?

[Steve Peterson]

I have a 1999 BMW 323i with an oil change recommendation of 15000 miles. I think I did an extra one at 7500 miles and have stuck with the factory spec ever since. The car has 170K miles and still going strong. Of course, they use full synthetic and good filters.

Steve

[Tom Stenzel]

There are engines with variable valve timing that require 5w-20 to run correctly. Using 5w-30 won't allow the camshaft phasing mechanisms to operate as expected and will trip the service engine light. Yes, the guys at the dealer will know why pretty quick.

I'm not familiar with Mazda engines at all. 5w-30 weight may be fine, it may not. Synthetic may be required, it may not.

Myself I'd follow the manual until the warranty was up. Also look in the manual to see what THEY describe as severe duty.

-Tom

[Phil Thien]

It's clear that the dealer just wants to do more service on your car. Dealers make a lot of money on service these days.

Pretty much what I've observed, too.

[Doug Carpenter]

I'd just be happy that your wife cares about the oil at all! My wife shrugs it off when ever mentioned. I get that it is my thing to deal with but I swear sooner or later we'll lose a car over it. lol

[Brian Elfert]

I had a VW Golf TDI. VW required synthetic diesel oil and the oil change interval was 10,000 miles. The oil filter is a cartridge type and not spin-on. I had no qualms about a 10,000 mile oil change since the manufacturer specified it. My 2012 Dodge Grand Caravan has an oil life monitor. The manual says to change the oil when indicated, or every 8,000 miles if the oil life monitor has not activated. I usually get between 7,000 and 8,000 miles before the "oil change required" message shows up.

[Jim Becker]

I go by the manufacturer's service intervals in the manual. For my 2012 Grand Cherokee Summit, that is 8000 miles. (MY14 is 10K miles) I do use synthetic oil and have done so for many years.

I question the dealer stating that you should use the lower interval because of "cold and salt". Those are not normally listed as "rough use" things by the manufacturer. Heavy towing, substantial off-road use, taxi service, etc., generally shift things to the lower interval under manufacturer specifications. Your owner's manual will tell you what is considered "rough use" for your particular vehicle. In my experience, dealer service departments typically push for lower fluid change intervals because of...profit. We had one local dealer that pushed so hard on that point that we have never returned to them for that vehicle and just use a local independent shop for everything except warranty work.

[Bob Turkovich]

I go by the manufacturer's service intervals in the manual. For my 2012 Grand Cherokee Summit, that is 8000 miles. (MY14 is 10K miles) I do use synthetic oil and have done so for many years.

I question the dealer stating that you should use the lower interval because of "cold and salt". Those are not normally listed as "rough use" things by the manufacturer. Heavy towing, substantial off-road use, taxi service, etc., generally shift things to the lower interval under manufacturer specifications. Your owner's manual will tell you what is considered "rough use" for your particular vehicle. In my experience, dealer service departments typically push for lower fluid change intervals because of...profit..

Ditto to Jim's advice. Always follow the manufacturer's recommendations...always. They aren't written in a vacuum.

The primary deteriorating factor for engine oil (and transmission fluid for that matter) is temperature. The "change oil" light algorithms on most recent vehicles are primarily based on oil time@temperature histograms stored in the engine controller. Obviously, heavy use such as trailer towing and stop-and-go driving will fill in the histogram quicker. Cold & salt should have no effect on oil longevity.

I also recommend never putting any additives/supplements into your vehicles' fluids (at least while it is still on warranty) as there is no way the OEM's can verify every additive out there and there is no way the additive supplier can confirm full material compatibility with every manufacturers' system. (Some additives may offer help to some vehicles. You just can't be sure which ones.) The only safe additive I can recall (pre-retirement) is Chevron Techron for fuel injector cleaning as all the major injector suppliers had verified compatibility with their injector interior components.

Anything else recommended by the dealer is purely for profit.

[Stan Calow]

My dealer's mechanic refused to change the oil at 3,000 on my new truck saying the manufacturer recommended 10K and they stood by that.