Engine oil

[Soundguy]

I thinkt he turbo cool down and bearing coking might be more of a concern for turbo diesels.. vs turbo gas engines. I have a pyrometer and like to get it down to 300-400 before shutting down. If I've been operating at interstate speeds or load for a duration especially.

lastly. One of my trucks is geared low.. 4.88 rear in a 99 ford f450 I turn 2750 rpm to KINDA stay with traffic on the interstate.. yellow area on my tach starts at about 3300 or 3400.. so i'm real close to max rpm.. in this application.. I like a synthetic oil. IE.. I consider that 'extreme' or severe duty.

If those trucks were just yard tenders or sometng I'd be running dino in them. but the 250, 350 and 450 get the snot worked out of them. The 250 actually had been throwing turbo underpressure codes for a while.. i switched to syn and within 2 weeks the issue went away and has never returned. previous to that the 250 had been on motorcraft psd 15w40... not a cheap oil for a dino either... coincidence? possibly.. possibly not..

Fair enough... I agree regarding startup and cold flow properties of synthetic for folks that live in extremely cold regions. That would be a viable benefit in that case. While I agree the molecular alignment of synthetic makes it more predictable, the base stock and add pack quality of today's conventional oil provides a film strength capable of paralleling that of synthetic. Comparison UOA's in my industry confirms that over and over again. Just about 100% of film loss is related to shearing out of grade which would be more relative to oil grade (weight) and very little to do with base stock difference. In short lighter weight oils have less shear resistance under load and heat which makes it important to choose according to your mileage or protection preference. Personally I just stick with 15w40 for a general industry accepted balance.

Regarding coking of turbo bearings, today's oils are nearly absent of sludge and carbon forming paraffin. This isn't an issue as it was years ago when there was a need for post lube and cool down timers. But I agree a little cool down is good insurance when EGT's are above 500 degrees or so. I just don't see the need for post lube systems and timers with today's lubes. It's a shame that companies try to use old school concerns to sell old ideas in a modern environment.

 

[kenmac]

Over the years I've learned that oil is oil.

Sure it is. That's why a lot of the high end vehicles come off the assy. line with dino

 

[Thomabear]

Sure it is. That's why a lot of the high end vehicles come off the assy. line with dino

I agree, VERY few vehicles ship with synthetic oil. Maybe 1 in a 1000 if that. And I doubt mfg's would ship ANYTHING w/o the proper protection... They must feel Dino protects just fine... After all they are on the hook for the first 100k

 

[kenmac]

I agree, VERY few vehicles ship with synthetic oil. Maybe 1 in a 1000 if that. And I doubt mfg's would ship ANYTHING w/o the proper protection... They must feel Dino protects just fine... After all they are on the hook for the first 100k

why do you feel this Synthetic Engine Oils - BMW North America high end auto maker prefers synthetic oil over dino ? Guess they don't have the info you have. If they had the info you have, they wouldn't be wasting $$$ on an synthetic oil

 

[Peacock]

I agree, VERY few vehicles ship with synthetic oil. Maybe 1 in a 1000 if that. And I doubt mfg's would ship ANYTHING w/o the proper protection... They must feel Dino protects just fine... After all they are on the hook for the first 100k

Not true at all. Many vehicles come with synthetic oil these days. Nearly all Euro cars, most every performance domestic and even most current Hondas.

 

[kenmac]

Not true at all. Many vehicles come with synthetic oil these days. Nearly all Euro cars, most every performance domestic and even most current Hondas.

Don't think he understood what I was saying in my post. Glad you could spell it out for him

 

[TomSeller]

Me, I can't make up my mind. Dino in some, syn in some, blend in some. Just playing the field. Haha

Actually, I use syn unless the engine consumes oil using syn. Then I try blend. If tolerable I stay with blend. Some engines like my Caddy Deville Northstar will only take Dino unless I top off the oil at every fuel stop. So I stay with dino on that one. I have a Briggs BCS 8 HP IC rototiller engine that is the same way.

 

[crazyal]

When I was a kid I got a generic riding mower at the dump. The guy dropping it off said it would burn oil almost as fast as gas. Since it was better than the push mower I took it home. I found that 85w gear oil worked great in the 12hp Briggs. It would pop and snap when you shut it off but it ran for years without an oil change. Never burnt a drop of oil. I eventually gave it away filling in the new owner. I don't know how long it ran for but it always amazed me. Granted the Briggs has splash lubrication and I never mowed in the dead of winter when it was -30 out.

 

[Midniteoyl]

Air bubbles also give anything that is hydraulically actuated the fits (ex. - basic valve lifter).

Soundguy listed 2 of my favourite reasons for using synthetic. With what some guys haul with "light" trucks, esp. turbo-dzl, the Engine Oil Temperature is probably higher than you'd suspect.

Recently, I've gone to running conventional in an older Honda car - high mileage summer use vs. $ was the reason. I'd add that synthetic often has a lower consumption rate (volatility, etc.) in a well maintained motor. I've also seen the same lower synth consumption pattern with my 7.3 diesel. Now that Winter is here, I'm back to synth in both vehicles.

With me checking oil levels fairly often, Conv. or Synth can both serve in my Summer applications.

Average consumer (ie. not a TBN gearhead like us) ? Different story. I see plenty of vehicles at my buddy's shop, extremely low on oil, if not out. A recent one needs a motor in a Mazda 6, that isn't much more than 5 years old.

I agree, today's conventional oil has come a long way from when I was a kid. Changed at engine OEM intervals, in spec conventional oil will serve fine for most applications.

That said, if I was turning my wife or offspring loose with a vehicle for an extended period of time "unsupervised", I'd want synth in it, just so I wouldn't have to be nagging (so much ) about checking the oil level.

Rgds, D.

In my 187K mile Audi, the Mobil 5w-40 I was using disappeared faster than the Mobil 10w-40 High Mileage stuff.. So I used that in summer, and the 5w in winter.

 

[Midniteoyl]

I thinkt he turbo cool down and bearing coking might be more of a concern for turbo diesels.. vs turbo gas engines. I have a pyrometer and like to get it down to 300-400 before shutting down. If I've been operating at interstate speeds or load for a duration especially.

..

Some turbo cars actually came with a 1 min timer to run the engine for 1 min after the key was turned off.. Freaked me out at first