Oil weight... Should I be worried?

[SoCal Tom]

Consumer reports did a study on oil changes about 10 years ago, They primarily focused on cabs, since they rack up a lot of miles quickly, in the worst service ( stop and go city driving). What they found was that changing the oil more frequently than about 7500 miles wastes money, because if you save the money you would have used on the oil changes you can afford the repairs that come along sooner, and you reduce the amount of wasted oil.
Personally I use change the oil about every 100 hours of operation. (My JK dash display has an hour meter built in.) In city driving, that works out to about every 3500 miles, but with highway driving its more like 6K to 7500 miles. Highway miles are easier on oil because the oil gets warm and cooks off the accumulated water that condensed in the engine. City miles rarely warm the engine up enough to do that.
Tom

 

[A3M0N]

Here is the response to an email sent to Jeep customer service:

Dear Richie:

Thank you for contacting the Jeep Customer Assistance Center.

When service is required, Chrysler Group recommends that only Mopar®
brand parts, lubricants and chemicals be used. Mopar® provides the best
engineered products for servicing Chrysler Group vehicles.

Only lubricants bearing designations defined by the following
organization should be used.

Society of Automotive Engineers (SAE)
American Petroleum Institute (API)
National Lubricating Grease Institute (NLGI)
API SERVICE GRADE CERTIFIED
Use an engine oil that is API Certified. MOPAR® provides engine oils,
that meet or exceed this requirement.

Use only engine oils with multiple viscosities such as 5W-30 or 10W-30.
These are specified with a dual SAE viscosity grade which indicates the
cold-to-hot temperature viscosity range. Select an engine oil that is
best suited to your particular temperature range and variation.

According to our records, the manufacturer does not recommend or
authorized the use of 5W-20 in the 4.0L I-6 Power Tech Engine in your
2002 Jeep Grand Cherokee.

Thanks again for your email.

Sincerely,

Tony

Customer Service Representative
Jeep Customer Assistance Center

Emphasis added by me.

Looks like I'm having my oil changed back.

 

[FordGuy1]

So full syn or semi? I have been using valvoline full syn but it has been using it a little more quickly than I like. No leaks or smoke. Changed the PCV out three times so thats not it.

Sent from my SAMSUNG-SGH-I747 using Tapatalk

Full Syn is better for sure, but semi syn changed every 5k with a quality filter is just fine.

 

[FordGuy1]

Consumer reports did a study on oil changes about 10 years ago, They primarily focused on cabs, since they rack up a lot of miles quickly, in the worst service ( stop and go city driving). What they found was that changing the oil more frequently than about 7500 miles wastes money, because if you save the money you would have used on the oil changes you can afford the repairs that come along sooner, and you reduce the amount of wasted oil.
Personally I use change the oil about every 100 hours of operation. (My JK dash display has an hour meter built in.) In city driving, that works out to about every 3500 miles, but with highway driving its more like 6K to 7500 miles. Highway miles are easier on oil because the oil gets warm and cooks off the accumulated water that condensed in the engine. City miles rarely warm the engine up enough to do that.
Tom

There is a lot of discussions about this topic, and I am no engineer. What I do know is we do about 60 oil changes a day, and I have been at the same dealer for 25 years. The customers who change their oil every 5k are typically the customers who have by far the best luck with engine durability. This is real world. We are having so may failures on the 10k intervals, and the aftermarket oil filters are falling apart at 10k causing all kinds of VCT failures. The cost between 5k and 7500 is nothing, plus if you want good tire wear rotates are every 5k anyway.

 

[Payback]

I wouldn't push the 4.0 out to 6000 mile changes. It is is an old tractor engine with some high tech doodads added to it. It needs to be changed more regularly.

And this is based on what? Because I get my oil tested by Blackstone Labs, and they're telling me my oil can last SIGNIFICANTLY longer than the standard 3k miles you're suggesting. Oil changes cost money that adds up quickly. Oil analysis is cheap. Base your advice on facts, not the lessons you learned from your father when you were a kid.

 

[reece146]

Instead of writing logical fallacies share your method and data.

 

[Payback]

Instead of writing logical fallacies share your method and data.

This is basically the same thing I wrote to you...

My method is take an oil sample every time I change the oil and have it anaylized. My data (no idea how to upload it on here) is that after 6,500 miles of driving I can still go a little more before the oil (full synthetic Mobile 1) isn't protecting my engine adequately anymore. I'm going to drive for 7,500 miles this go-round and see what the lab says. Fact-based decision making...

 

[reece146]

Give us the highlights of your test? Fe, Cu, Mg, Zinc?

Service usage? Gravel roads or 100% pavement? Filtration? Was this even in a Jeep 4.0? Vintage? Mileage? You didn't say.

My data is primitive. When pulling Mobil 1 at 3000-5000 miles on my 2001 XJ it visibly looks terrible compared to pulling the oil on my 08 Civic (K20) and `13 A4 at ~7500+ miles.

Good luck.

 

[M35A2]

Has anyone compared engine clearance specifications for engines of the same family with different viscosity recommendations for different model years?

If the same engine has the same clearances, but the recommendation changed to thinner oil, then I suppose the change is for fuel mileage.

If, on the other hand, the engines that have thinner oil also have tighter clearances, then I suppose these engines are indeed designed for thinner oil.

 

[Payback]

Give us the highlights of your test? Fe, Cu, Mg, Zinc?

Service usage? Gravel roads or 100% pavement? Filtration? Was this even in a Jeep 4.0? Vintage? Mileage? You didn't say.

My data is primitive. When pulling Mobil 1 at 3000-5000 miles on my 2001 XJ it visibly looks terrible compared to pulling the oil on my 08 Civic (K20) and `13 A4 at ~7500+ miles.

Good luck.

For whatever reason I can't seem to access the result online, and my paper copies are packed up (Just moved back from Okinawa, Japan and haven't gotten my stuff back yet). But I CAN tell you that even if I did have them, those numbers wouldn't mean anything to me. Which is exactly why I pay the $20-$30 to have a professional look over them.

After reading over my last post I think I came on a little heavy, I'm sorry if I sounded like an ************, not my intent. I was just trying to point out the fact that there are plenty of resources available for the common-man nowadays that give us the opportunity to be 100% sure we are protecting our engines. There's no need to waste money, time, or material when all we have to do is fill a plastic cup when we are changing the oil and mail it in. A few weeks later, boom, you've got a 1-2 paragraph explanation on how healthy your engine is and if you need to be on the lookout for anything. Doesn't get much easier than that, plus it could save you a lot of money. Both in maintenance and misc cost that come from unexpected engine failure.