Does a Turbo diesel engine NEED synthetic oil?

[Thermo1223]

I'm happy to pay $1.42 more per gallon to get full synthetic.

It's not the full synthetic you think it is.

 

[whizbyu]

I knew that. Thats what oil companies do. But I was at one point a practicing Catholic and my mom forced me to go to communion and confession to make sure I have a ticket to The Place.
Peace out

 

[YZJB]

Always wondered about this. The new diesels can run 1000 degree egts while in regen at a stop light. Turbo seals definitely take a beating on these newer trucks. I don't know many people who idle before shutdown. The larger semi trucks have a better design than the smaller consumer pickups which inject extra fuel on the exhaust stroke to make more heat for the aftertreatment system. The semis have an injector in the exhaust so the engine isn't subjected to all that extra heat.

EGTs in the exhaust manifold and turbo do not increase all that much during a DPF regen as the extra fuel burns in the DPF not the turbo.

 

[jesco88]

Hey all, just been following this thread and many like it for sometime. Just was letting youtube play random videos while I worked, and my ears were tingling when I heard about deposits and synthetic oil.
The link should start at 8:09, where a Valvoline engineer is talking about how synthetic oil increases the temp before deposits will form on piston rings. Might be interesting or applicable to this discussion.

 

[userfriendly]

Valvoline engineer? What’s that?

 

[jesco88]

Valvoline engineer? What’s that?

Uh-oh... What did Valvoline do? lol

 

[The motor guy]

EGTs in the exhaust manifold and turbo do not increase all that much during a DPF regen as the extra fuel burns in the DPF not the turbo.

I disagree. Remember the 6.4 powerstroke? They picked to rear two cylinders to do regen. Those two were always the first be be worn out.

 

[YZJB]

I disagree. Remember the 6.4 powerstroke? They picked to rear two cylinders to do regen. Those two were always the first be be worn out.

Yep because of fuel washing the oil off the bores. I’m talking turbo temps.

 

[Braapdaddy]

At one point I had Four 6.4 powerstrkes at once ...... still have 2 today they happen to be my favorite generation SD visually

Never had synthetic just 15w40
Mystik
Castrol GTX
Lucas long drain

Castrol GTX 15w40 ( 15 gallons )on deck ready to go

I have had these engines apart from crankshaft to oil cap and everywhere in between

 

[userfriendly]

At one point I had Four 6.4 powerstrkes at once ...... still have 2 today they happen to be my favorite generation SD visually

Never had synthetic just 15w40
Mystik
Castrol GTX
Lucas long drain

Castrol GTX 15w40 ( 15 gallons )on deck ready to go

I have had these engines apart from crankshaft to oil cap and everywhere in between

That shouldn’t surprise anyone.

 

[Braapdaddy]

That shouldn’t surprise anyone.

Once the remaining two went on a diet they are very dependable and the F350 I wouldn't hesitate to take across the country it's built to last not for horsepower it's my plow truck

The spare truck for my spare trucks is on the original block and heads at 195k but it definitely sufferd before it was given a second chance to breathe

 

[Fishstyx]

I've heard this a lot, Turbo charged engines "need" synthetic oil to prevent coking of the oil on the bearings in the turbo after you turn the engine off. I always idle 3-4 minutes when I park after highway driving and maybe 2.5 minutes after stop and go driving. The idea is to let oil circulate and carry heat away from the bearings in the turbo and to cool it off.

Some say synthetic oil is necessary for this. idk. Most 15w-40 oil is conventional or synthetic blend. There's not a lot of synthetic 15w-40 out there, just Amsoil 15w-40, Mobil 1 extreme 15w-40, T6 15w-40 etc. I'm currently running Orielly 15w-40 in my Yanmar powered turbo diesel tractor (Deere) because the dealership didn't have any plus 50 II 15w-40. Orielly 15w-40 meets all the specs for it.

No it doesn’t neither do gasoline engines. However full synthetic motor oils are far superior to conventional mineral oil and don’t breakdown easily which is why synthetic motor oils should be used. But it’s up to you personally full synthetic is the only way to go.

 

[Highlander 1459]

most modern turbo diesel engine have a water cooled turbo( or at least the bearing housing) , so the answer about coking is no.
that said, do you need synthetic in a diesel..
probably not... it just depends on how much you want to spend
in order the feel all warm and fuzzy..

 

[userfriendly]

most modern turbo diesel engine have a water cooled turbo( or at least the bearing housing) , so the answer about coking is no.
that said, do you need synthetic in a diesel..
probably not... it just depends on how much you want to spend
in order the feel all warm and fuzzy..

$3 Brotella quality that meets CK-4 is warm and fuzzy enough for me and I don’t have to run it forever to get my money’s worth.
I’ll save the so called $7 synthetic for winter when 0w or 5w something is needed for cold start performance.

 

[Fahrvergnügen]

most modern turbo diesel engine have a water cooled turbo( or at least the bearing housing) , so the answer about coking is no.
that said, do you need synthetic in a diesel..
probably not... it just depends on how much you want to spend
in order the feel all warm and fuzzy..

The water cooling is for heat soak. Problem is you have a turbine spinning X amount of RPM, I’ll use my super duty as an example, so driving on interstate unloaded oil temp runs about 203-208 in summer driving 70mph So now you pull up to say Sam’s, that oil temp is cooling down yes as your sitting in traffic lights but your trying to cool 13 quarts of oil. Do you pull up to Sam’s oil temp is 200
Degrees, you shut off the engine, you have now shut off the oil supply that was pumping the oil through the coolers, so you have now a turbine that is still spinning and oil that is 200 degrees. For actually recommends shutting down a scorpion with an oil temp of 194 degrees. My tuck takes 2-3 minutes to get down to that temp. Now let’s talk about a loaded super duty now. Mine towing a grand design solitude 15,000 pounds runs an oil temp of 210-230 degrees depending on grade. So now you have oil that hot and you shutdown , it’s just not good for the bearing. It takes my truck 15 minutes of idle to go from 220 degrees oil temp to 194 degrees and it’s a nice smooth shutdown. It’s not smooth when you just shut them off hot I don’t do it to mine but have watched people at campground do it and it sounds bad. So the water cooled turbo is good, but it’s for heat soak. Doesn’t do anything for the bearing and oil supply.

 

[Highlander 1459]

It’s not smooth when you just shut them off hot I don’t do it to mine but have watched people at campground do it and it sounds bad. So the water cooled turbo is good, but it’s for heat soak. Doesn’t do anything for the bearing and oil supply.

your answer really has nothing to do with whether you need a synthetic in a diesel but how long it takes for oil to cool down.