allisojh wrote:Mobil 1, Mobil 1 filter.

Nothing else needed.

8-9k easy between changes

purrs like a kitten when the heat shields are not rattling!!!

Ha ha, no kidding. These R51 Paths are noisy in that department (at least the V8 is).

By the way, I too am a fan of Mobil1 and used it for years in my wife's vehicle and my previous vehicle before the PF. What grade are you using? 5W-30, 10W-30, maybe something else? I'm in the Midwest where we get relatively cold winters (nothing like Canada) and hot summers where it's not unusual to spend a month or so in the low-90s.

If you guys are changing oil every 10k that's probably a year's worth of driving for me. I'd like something to run the full gamut but also want what Nissan advises is a suitable option.

I'm using the 0W-30. It's supposed to help with MPGs, so it can't hurt. I don't think it is, but it's the same price as the 5W-30.

volvite wrote:I'm using the 0W-30. It's supposed to help with MPGs, so it can't hurt. I don't think it is, but it's the same price as the 5W-30.

Running water would also help with mpg. And it wouldn't hurt at first It's "probably" okay (particularly since it's the cold weather rating) but here's some stuff to think about.

Most wear surfaces, particularly journal bearings, are designed hand in hand with the chosen lubricant, almost entirely for viscosity. We crunch a bunch of factors to come up with things like the Sommerfeld number and use Raymondi-Boyd charts to design the bearing as well as identify a range of viscosities acceptable.

At one end will be minimum viscosity, which comes with minimum bearing drag and minimum heat produced in the bearing. But it also comes with maximum bearing eccentricity with the thinner fluid wedge (offset distance of the center of the shaft from the center of the journal) and maximum wear. At the other end is maximum viscosity, which comes with max bearing drag from working the fluid, but also maximum protection.

It's likely that the manufacturer specified an oil range in between the minimum and max. But you don't know why they did what they did so it's hard to make an educated guess as to what's a good or bad idea. But generally erring on the minimum viscosity side is probably not good. Here's why.

Most auto manufacturers will kill for a tenth of a mpg higher CAFE scores. One place you can get that is out of oil viscosity. For a while they were allowed within the rules to deliver the vehicle with a lower viscosity oil while specifying a higher viscosity oil. So the vehicles tested would get the tiny benefit while the end user would eventually replace the oil with something the engine was really intended to use.

Sometime in the last ten years or so they changed the rules, so the specified oil must match the delivered oil. So a lot of manufacturers simply lowered the viscosity specified for the vehicle, rather than take the hit on the CAFE number.

Did they go back and redesign engines across the board? Of course not...that would also reduce their CAFE scoring. So they chose mpg over engine longetivity for you.

Our 4.0L was released after that period of time, so it's not likely they fudged that way. But I guarantee you they are squeezing what they can out of viscosity among other things to get the highest score possible, which means the OEM spec in your manual is already on the low side of the Raymondi-Boyd curve.

Most of us won't keep our vehicles long enough to see the end of the engine's life span. However...no reason to bring it about sooner rather than later...

Great insight, ShipFixer.

However, wouldn't your comments be more applicable to Honda's wholesale change from 5w30 to 5w20, versus what volvite is talking about which is 5w30 vs 0w30?

t

disallow wrote:Great insight, ShipFixer.

However, wouldn't your comments be more applicable to Honda's wholesale change from 5w30 to 5w20, versus what volvite is talking about which is 5w30 vs 0w30?

t

I would go along with that too particularly if the move to Xw20 was dino oil. Since this move requires at least a synthetic blend I don't believe there is as much concern. I've had sampling done on a Toyota (which has made the same move across all products) at 10k intervals and the 0w-20 was doing a fine job.

disallow wrote:Great insight, ShipFixer.

However, wouldn't your comments be more applicable to Honda's wholesale change from 5w30 to 5w20, versus what volvite is talking about which is 5w30 vs 0w30?

t

Well, I did caveat that it probably doesn't matter much as its the cold weather rating. May not matter at all depending on the winter...

Honda wasn't the only manufacturer to do so but yeah, that was kind of the play. IMO they kind of screwed the consumer by making the choice for you. There's lots of nonsense out there about engine oil, but "lower range viscosity = higher mpg" vs "higher range viscosity = better wear protection" can be handed to the consumer...

Anyone want to throw me a bone and comment on what the owner's manual calls for? I've read a lot of it so far, mainly dealing with all the creature comforts that come with the LE V8 model but have not stumbled upon the recommended oil weight mostly because it just had an oil change two or three hundred miles ago at the dealer.

5w-30. There's a separate maintenance manual that covers intervals...I believe it says 5,500 for taxi/towing/severe service, and 7,500 for non-severe service.

Knowing it's a can of worms, I should throw this out there. Oil additives (Lucas, Slick 50, Seafoam, et al.) are not a good idea. If anything they're in addition to the additives already in your oil (friction modifiers, detergents, etc.) and will only dilute the oil and otherwise remove it from spec. Outside of JASO, API, SAE and other specifications each manufacturer has its own blend of additives; it's unknown how the extra additive will interact with each one and your engine.

There is some academic argument for using other specs of oil. For instance diesel engine oils are similar to previous API specifications that had higher amounts of things like zinc dithiophosphate and other phosphates which will provide greater protection in extreme conditions where metal to metal contact is more likely. So motorcyclists will sometimes use things like Shell Rotella-T since the transmission and wet clutch share the oil supply and sump with the engine.

But you can get there directly with that spec and retain viscosity and other critical parameters that an additive may impact otherwise. The laboratory and anecdotal evidence for additives is otherwise insufficient to not good.

I know things like Seafoam will do wild things like clean carbon off the bottom of piston heads and I believe it. However...when it does something like that you should wonder what else it is doing...

"Oil additives (Lucas, Slick 50, Seafoam, et al.) are not a good idea."
Good question, I use Slick 50 in three of my Chev trucks (early to mid 90's) and never had a problem. Now with these newer engines I don't know if it's a good idea to use oil additives.

I've got 452,000 miles combined on all 3 of my Nissans and have never used any oil additives.

Not to mention an additional 60,000 on a Hyundai Genesis and again, no additives ever used, no problems thus far on either vehicle.

Calicajun wrote:"Oil additives (Lucas, Slick 50, Seafoam, et al.) are not a good idea."
Good question, I use Slick 50 in three of my Chev trucks (early to mid 90's) and never had a problem. Now with these newer engines I don't know if it's a good idea to use oil additives.

Wasn't a good idea then either - a couple of my Chevy-owning friends in the 90's had engines replaced after using Slick 50. That was a long time ago so I don't remember all the details (I think Slick 50 covered the engine replacement), but in general additives = bad.

Something to think about. Many of these like Seafoam can be used in the 5qt oil sump or the 20 gallon fuel tank. Seafoam is known to be a *very* good solvent, one of the best I've ever used.

If my engine runs better 20 minutes after running it through the fuel tank then it must surely do a great job in the crankcase. (I know it does, as I had some mechanics that worked for me who would vouch for it.) However, to do that it's a pretty strong solvent/detergent. What else is it doing? What else is getting broken down? How far does it make the lubricant deviate from SAE or API specs and in what way?

You just don't know. It could be benign (probably is for tens of thousands of miles on average or the market backlash would be severe). It might not be (if it's not noticeable for thousands of miles then the failure is hard to tie to the additive).

Since the engine manufacturer is now pushing the minimum viscosity spec for the engine for mileage, anything that might reduce viscosity is therefore more risky than it would have been previously...

Use Slick 50 in my Chey's, a 90 1500 pick up and 93 1500 Suburban both 125,000 miles on them before selling each one off. Lot of those miles were pulling a 30 foot travel trailer, about 5,200 lbs, with out any problems. From what I have been reading about todays engines, they are made different coming with their own coatings on the cylinders. So I don't think I'll take the chance of putting in any additives this time around. I'll just stick to synthetic oil and keep reading this forum.

Yep, I'm on the fence when it comes to some oil additives. I've used Duralube in my older cars, and they didn't explode. Whether the product did anything to help, I guess we could argue. I think it did. Car had issue with oil burning and hesitation before, after using the product it did not.

I've run Lucas Synthetic Oil Stabilizer in both my old 98 civic and in my 05 path. My 98 civic had 190psi compression with +/- less than 5psi at 300k kms (186k mi). That is what it was from the factory. Was that because of the oil additive? No idea.

With the Pathy, I've never had to do my timing chain tensioners, though I am sure I had heard the noise under acceleration when the engine was cold several times. Since running the oil stabilizer, I've never heard it.

Once again, not very scientific. I always loved the sales displays for these, which tell you NOTHING about how the product will perform when actually at operating temperature. Maybe you've seen the display with some plastic gears in it, you turn the conventional oil side and the oil basically does nothing, but with the product in it, it bonds to the gears better to 'ensure better lubrication'. That is a joke for sure.

I've also had luck with the Lucas Oil Power Steering additive in my 2000 Grand Prix GT. Pump was leaking, and making noise. Put 1/2 of the $10 bottle of fluid in, and it hasn't leaked a drop since, and is much, much quieter.

So there! Explain my completely non-imperical and non-measureable experiences!

t

Calicajun wrote:Use Slick 50 in my Chey's, a 90 1500 pick up and 93 1500 Suburban both 125,000 miles on them before selling each one off. Lot of those miles were pulling a 30 foot travel trailer, about 5,200 lbs, with out any problems. From what I have been reading about todays engines, they are made different coming with their own coatings on the cylinders. So I don't think I'll take the chance of putting in any additives this time around. I'll just stick to synthetic oil and keep reading this forum.

Most engines today still use plateau-honed iron sleeves or liners, if not an iron block. There are some different technologies out there such as the old Nikasil liners used by BMW (aluminum block with a harder secondary phase like Nickel and Silicon; the bores are machined straight and then the aluminum is acid-etched away leaving the harder wear surface at the original surface boundary with space in between for oil entrapment), but most are still iron.

Just as with other wear surfaces in the engine, the piston rings are riding on a layer of lubricant, and therefore the viscosity of the lubricant is what matters most. I'm sketchy on things that mess with that...everything else in your oil (detergents, stabilizers, friction modifiers, etc.) is there to either preserve viscosity or perform some secondary function like entrap dirt or water...