Point Blank- Will using a HDEO 15w-40 Hurt a new engine

[like a rock]

Yes I know about the warranty issues, but do you think with the tighter tolerances in todays newer engines that this oil would cause increased operating temperatures which could lead to greater wear? My concern is the new SM motor oils not containing enough zinc and phos. among other things. I may even run this oil year round because of all the short trips to work. It seems that these oils are the way to go and the pcmo's are more about cafe issues which may lead to increased wear even in the new SM oils. Let us have a debate.

 

[Jelly]

I definitely don't recommend using a HDEO 15w-40 in a new gasoline engine unless the grade is recommended (which very few new cars recommend) and you just don't want to spend a bunch on a synthetic. Stick to the manufacturers recommendations/requirements at least until the warranty is up and use a good syn-lube. I wouldn't use a mineral based PCEO though, be it SL or SM! Are PCEO's more about CAFE issues? Sure, without a doubt. Will a 15w-40 hurt a new engine? Well, if the temperature was cold enough, depending upon the engine is question...without a doubt! European gas engine manufacturers state that modern 15w-40's are good down to 15F or so, and I have no reason to think otherwise. Use a mineral based 15w-40 in very cold weather in a brand new "super-tight" modern engine, and you're beggin' for trouble... Increased engine temperature and lower fuel economy is very plausible though in comparison to say a 9cSt 20 weight oil. The engine is being forced to run through a much thicker hydrodynamic film, and while this does provide much better protection (fluid film is always better than a mixed-film/boundary film), it's still much harder to "run" through than air... In regards to a new vehicle, just run a top-quality PCEO synthetic lube (Redline, Amsoil, Mobil, etc, etc, etc...) of the "recommended" viscosity and you'll be set. What kind of vehicle do you have? What condition is the engine in (consumption, etc..)? [ April 26, 2004, 07:50 PM: Message edited by: Jelly ]

 

[KW]

I have nothing to back me up but I would say that it would not hurt you motor at all. I am not a believer in the tighter clearances that is often talked about. The motor swells when it gets up to temp and must stay within a certian tolerance range or it will beat it's self to death or lock up. The HDMO's are good oils to use unless you are burning a lot of oil and the zinc will kill the converter.

 

[Jelly]

quote:

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Originally posted by KW: The HDMO's are good oils to use unless you are burning a lot of oil and the zinc will kill the converter.

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In comparison to a PCEO mineral-lube used before, changing to a HDEO 15w-40 can drastically reduce consumption, and combined with less "burn-off", I'll bet you that less phosphorus (BTW, phosphorus is what suposedly "kills" catalytic converters, not zinc) is being passed downstream.

 

[sbc350gearhead]

They also make 10w30 HDEO's.

 

[Jelly]

quote:

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Originally posted by KW: I have nothing to back me up but I would say that it would not hurt you motor at all. I am not a believer in the tighter clearances that is often talked about. The motor swells when it gets up to temp and must stay within a certian tolerance range or it will beat it's self to death or lock up.

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Sure, but what are the clearances (and tolerance range) of a '80's mid-displacement OHV engine and a '04 small-displacement OHC engine (Figuring both are normal, everyday passenger cars)? What do the oiling systems of each look like and what gets oil first on startup? No trying to start an argument with you (Remember, I'm a big fan of HDEO's and defend them every flippin' day). [ April 26, 2004, 08:59 PM: Message edited by: Jelly ]

 

[KW]

quote:

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Originally posted by Jelly: [/qb]

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(BTW, phosphorus is what suposedly "kills" catalytic converters, not zinc) is being passed downstream. [/QB][/QUOTE] That's what I ment to say (phosphorus) Thanks

 

[Jelly]

Welcome.

 

[KW]

Some oil the crank first like a Chevy V8 and other oil the lifters first like a Pontiac V8. The reason I don't buy in to the tighter fitting motors is all the start up main bearing rattle and piston slap the newer Ford and Chevy V8's have. It might have oil on it but it's still getting beat up. I pulled a Ford 4.6 down a few years ago and didn't see anything special in it other than the cams were the last things oiled. If I owned one I would put a felt wick above each cam lobe like you would see on a set of points. At least it would get some sort of lube during the first 30 seconds of operation before the oil gets there. In any of the motors that I have built only the crank, cam journals and lifter see much pressure feeding. Everything else seems to rely on splash. Heck I don't know I just tossed out my opinion to the group.

 

[Ken2]

quote:

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Originally posted by like a rock: Yes I know about the warranty issues, but do you think with the tighter tolerances in todays newer engines

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Clearance is the amount of gap in the bearings the manufacturer requires. Tolerance is the amount of error allowed. Yes, modern manufacturing practices reduce the error; the tolerance. The clearance has remained about the same for many years. Don't fret about the new ILSAC GF-4 oils and the future API SM service category. These oils are very extensively tested and will reduce wear and keep engines cleaner than present ILSAC GF-3 and API SL oils. Keep in mind that the car makers' finance divisions sell many extended service contracts for up to 100,000 miles. They don't want the expense of engine repairs under those service contracts. Also, the finance divisions lease many cars on three or four year leases. Many of the lessees don't do much in the way of maintenance, and the oil must hold up under this neglect. Ken

 

[Jelly]

quote:

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Originally posted by KW: Some oil the crank first like a Chevy V8 and other oil the lifters first like a Pontiac V8. The reason I don't buy in to the tighter fitting motors is all the start up main bearing rattle and piston slap the newer Ford and Chevy V8's have. It might have oil on it but it's still getting beat up. I pulled a Ford 4.6 down a few years ago and didn't see anything special in it other than the cams were the last things oiled. If I owned one I would put a felt wick above each cam lobe like you would see on a set of points. At least it would get some sort of lube during the first 30 seconds of operation before the oil gets there. In any of the motors that I have built only the crank, cam journals and lifter see much pressure feeding. Everything else seems to rely on splash. Heck I don't know I just tossed out my opinion to the group.

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Sorry if my post "up there" came out wrong...I don't know what the clearances are between old and new engines, nor do I know how the oiling systems differentiate. I was just hoping you would know what makes these new engines so special that they "must" use a low-vis oil or they'll destroy their top-ends!

 

[ToyotaNSaturn]

No, it won't. http://theoildrop.server101.com/cgi/ultimatebb.cgi?ubb=get_topic;f=3;t=000830#000000 If 15w-50 won't hurt a new engine, neither will 15w-40.

 

[TooSlick]

I'd feel comfortable running a 15w-40 in any new engine in temps above 50F, but I'd stick with 0w-30 or 5w-30 for temps < 50F. Modern engines are designed to use low viscosity lubes and the oil pump and oil passenges are sized accordingly. Oil flow to the upper parts of the engine is very critical for an OHC or DOHC design and the thicker 15w-40 simply won't pump as well. Oil pressure in cold weather with a 15w-40 will probably be excessive, so you will be shunting oil back to the pan all the time through the oil pressure relief valve.... Tooslick

 

[batterycar]

Isn't 15W-40 recommended for these same engines in Europe?

 

[JohnBrowning]

Well not knowing what the year, make or model is or the engine in question I will bite any ways. You are not going to cause any damage to your engine buy running 15W40 in warm spring and summer temps! You would safe running 15W40. My 15W40 bottle of Castrol Truck blend say on the bottle for temps above 10F. I have ran 20W50,15W50,5W40,5W50 and 10W30 in the following brands with both 4 cylinders,V6's,V8 OHC and OHV engines. Toyotas I4,V6,V8 Buick V6 Chevy SB 5.7 Geo Metro I3 Ford I4,I6 None of them made any strange noises, none of them experinced power lose or any noticeable fuel economy increase or decrease.

 

[Chris 2421]

I agree with John. The 15w40 won't hurt your engine,nor will it decrease your fuel economy.I've been using 15w40 in my 2002 Dodge Ram quad cab and no problems after 36K so far.Don't expect any either.