I think following the mfgs guidelines are sufficient. If your driving style fits the severe duty schedule, is there really all that much difference in changing between the recommended 3750 and 3000?

Since I do mainly hwy driving, I'm going w/ the 7500 mi intervals but using synthetic oil to ensure my oil goes the distance.

I think we should also consider the negative environmental impact of changing oil and oil filters at an accelerated schedule.

 

FWIW, mobil 1 still has the 7500 and 15,000 mile oils (more detergents).

And, they GUARANTEE it.

Would I go that long without changing my oil? Nope.

But, if an oil company is going to guarantee my engine during that time period, that pretty much sells me on the fact that you're just wasting money by changing the oil every 3k miles.


People care less about the environmental impact and more on the wallet impact.

 

How are you going to prove it was the oil failing, and that you've always used mobil 1? I Guarantee that mobil 1 has replaced less than 10 engines under this "guarantee"

 

Me likey likey crown also. Along with ****, and basil hayden

 

Just some food for thought, the service interval (for oil changes) on the 350Z in the UK is 9000 miles. From the dealer. Do you really think the engine oil gets that much hotter or dirtier in the US?
If you check any manufacturer that sells equivalent cars in Europe the oil change intervals are significantly higher than in the US. The dealers also make significantly more from the sale of the car so they don't need to get so much back from servicing. I had never seen anything like JiffyLube until I moved to the States. Trying to sell more oil anyone?

 

Probably right.

But, if it weren't safe, why would they recommend and guarantee it?

I'd bet Mobil has done a bit more testing on oil change intervals and its affect on engine wear than a bunch of car guys on a forum.

Plus, what would they have to gain by lying? If anything, they'd want to tell us to change our oil every 500 miles. More money for them.

 

Changing quality motor oil at 3000 miles in modern engines is a waste of time and natural resources. Unless you're running Land Rovers through the Sahara or driving 2 miles a day stop and go in frozen Greenland, your oil will protect your engine for at least double that number of miles.

 

Amsoil has had 25,000 mile intervals since it's inception in the 70's. I've been doing long drain intervals upwards of 20k since 1994 depending on the vehicle and I have yet to experience any problems with any of the engines. My 94 Honda Civic had 250k+ on it when I sold it to a Honda Mechanic at my dealership. I did 20k intervals on that vehicle with filter changes at the 10k mark. The engine internals looked almost brand spanking new. 3k is a complete waste of time, money and hurts the environment. 5k intervals with regular dino oil are sufficient. 10k minimum for Amsoil, Mobil 1 or EP, Penzoil Platinum, Redline or German Castrol Syntec.

 

What wallet impact? It would seem that changing the oil at the recommended 7500 mi interval would be cheapest. If people are concerned about the engine blowing up, you have your powertrain warranty and, as you indicate, Mobil 1 has their warranty as well.

Seems like following the recommended interval would be good for both the environment and your wallet no matter how you look at it.

 

I saw this article on line and dismissed it like all other opinions. When oil gets
dirty it needs to be changed regardless of what oil you use or how good you
think the oil filter is....dirty is dirty. I'll continue to change my oil regardless
of cost because I value my car and it's internals....my opinion!

 

Marketing.
What they have to gain by "lying" is that they have to have some "concrete" benefits to justify the additional cost of synthetics. Longer service intervals is one of them. Will the engine die if you use 10k intervals? Probably not. Will 3k intervals on synthetics yield less wear on the engine? Yes. Is that difference significant? Maybe. Do I want to take that chance? NO.

 

Your absolutely correct. However, the good synthetic oils are able to suspend the dirt better and the better filters are able to, well, filter better. 3k is a myth. The only way to know the condition of your oil is through oil analysis. I've done this for every vehicle I've owned since 1994. It tells you everything about the condition of your oil and 10k on a VQ35 motor is absolutely fine with the synthetics I listed in a previous post. Even dino oil is good for 5k. You cannot tell the condition of your oil by color.

 

Taste?

haha. I agree. W/o an analysis, everyone's advice is like shooting targets at night.

 

IMO changing oil every 3k miles is purely a marketing gimmick to generate for Jiffylube etc. I have seen no good science to support this. Go by mfr recommendations if using dino oil - 7000 miles for highway driving and 3500 miles for "severe" Use some common sense -since driving is a blend of both maybe every 5k or 6k is good. Fake synthetic "Type III" oils last longer; true Type IV PAO synthetics such as Amsoil last longer still (google bob is the oil guy). My experience is to change dino oil every 5k mi. and Mobil 1 every 7500 mi with mix of traffic and highway. I put about 100k on my past three cars miles on and all used less than 1/2 qt between changes.

Consider that changing oil unnecessarily pollutes the environment and wastes resources. Not just the oil itself but the gas getting to the oil change scammers and back, tire wear, vehicle depreciation, and your valuable time and money.

 

Changing oil every 3k miles was actually necessary, way back in the day.

Nowadays, engines run clean/well enough that it is not.

The number just stuck.