Oops. How bad is 15W-40 oil???

TxAshurst · **Posted:** Thu Jan 12, 2006 10:57 am

I never feel like I really own a car until I do an oil change, so I decided to change it on the CRD even though the dealership offered the first one free. So I was shopping for oil and I wanted something with a C1-4+ rating. I found some Delvac at Wally World that was 5W-40, but only by the case. Then I noticed gallon jugs of Delvac down the aisle a bit, so I grabbed two and went home to do the change.

BTW, that dirty Mobil 1 is Nasty stuff - nearly impossible to get off things like hands and tools.

Anyway, I put 3 quarts in the engine from the first jug, then as I opened the second jug I noticed it had a different pour spout than the first one, which led me to looking closely at the jugs. Ouch! They were both 15W-40 instead of 5W-40. Well, I had to press on at that point, so I put it in, tested for leaks, and went to bed.

So the question for all you diesel experts out there is: what is the impact on running with the wrong oil in there?
Can I get away with running it for a few thousand miles while the weather is cool?
If I have to change it out, do I also have to spring for a new filter (I installed a STP filter) ?

wenied · **Joined:** Wed Dec 21, 2005 4:01 pm **Posts:** 107

It'll be fine. You live in texas so I doubt you'll be seeing any sub zero temperatures. 15 is the oils viscosity at cold temperature and 40 is the viscosity when it's hot. Being is you used a 40 oil just like the book recommends and you wont be driving in antarctica I'd say you could use that 15W40 year round.

Oberkanone · **Joined:** Thu Oct 06, 2005 2:34 pm **Posts:** 26

The 15W-40 is a non-synthetic.
If this were my CRD, I would NOT leave non-synthetic, incorrect weight oil in my vehicle any longer than it would take to drive to the store and buy the correct oil.
During the oil change I would drain and re-use the oil filter, however, STP would not be on my list of choices for oil filters. Purolator, WIX, or NAPA Gold would be my recommendations for inexpensive, quality oil filters.

Guest · **Posted:** Thu Jan 12, 2006 4:17 pm

The turbo requires synthetic oil to lubricate it's bearings. Change it immediately or you will probably burn it out.

wenied · **Joined:** Wed Dec 21, 2005 4:01 pm **Posts:** 107

Bah..the dinosaur sauce is just fine for now. I just wouldn't keep it in there for more than 2000 miles or so.

TxAshurst · **Posted:** Thu Jan 12, 2006 5:06 pm

Thanks, fellahs.
I'm going to stop on my way home from work and get new oil and filter. It'll all go in tonight after dinner. :oops:

oldnavy · **Posted:** Thu Jan 12, 2006 5:11 pm

Just change it out at 3,000 miles and all will be right with the world and just allow a full minute for turbo to cool before shuting off engine under normal driving conditions.

Wenied the oil is 15w and does not change viscosity with temp, it just has the same heat capabilities as a 40w oil would a a specific temp. I have wondered for 30 years why people think the oil changes thickness or viscosity as temp rises or lowers.

LEDfoot · **Posted:** Thu Jan 12, 2006 5:14 pm

alljeep wrote:

The turbo requires synthetic oil to lubricate it's bearings. Change it immediately or you will probably burn it out.

Now that's entirely not true.
Synthetic is preferrable in a turbo because it doesn't break down as easily in hight temperatures.
If temp is kept within normal range (as it should in a stock engine) dino-oil will lubricate just as well.

Still, I wouldn't be so worried about switching immediately, but I would make this a short oil change interval (<2000).

Guest · **Posted:** Fri Jan 13, 2006 8:37 am

LEDfoot wrote:

alljeep wrote:

The turbo requires synthetic oil to lubricate it's bearings. Change it immediately or you will probably burn it out.

Now that's entirely not true.
Synthetic is preferrable in a turbo because it doesn't break down as easily in hight temperatures.
If temp is kept within normal range (as it should in a stock engine) dino-oil will lubricate just as well.

Still, I wouldn't be so worried about switching immediately, but I would make this a short oil change interval (<2000).

You will cook the regular dino oil, which can burn the bearings out as it passes through. The ports the oil travels through to lubricate the turbo are very small and the turbo is running at WAY above normal engine temperature and has no "coolant" of it's own.

My dealership already reported one incident of this to me when I quizzed him on how well they knew the CRD (just in case I need service in the future). Wrong oil, your risk.

Reggie · **Posted:** Fri Jan 13, 2006 10:02 am

alljeep wrote:

LEDfoot wrote:

alljeep wrote:

The turbo requires synthetic oil to lubricate it's bearings. Change it immediately or you will probably burn it out.

Now that's entirely not true.
Synthetic is preferrable in a turbo because it doesn't break down as easily in hight temperatures.
If temp is kept within normal range (as it should in a stock engine) dino-oil will lubricate just as well.

Still, I wouldn't be so worried about switching immediately, but I would make this a short oil change interval (<2000).

You will cook the regular dino oil, which can burn the bearings out as it passes through. The ports the oil travels through to lubricate the turbo are very small and the turbo is running at WAY above normal engine temperature and has no "coolant" of it's own.

My dealership already reported one incident of this to me when I quizzed him on how well they knew the CRD (just in case I need service in the future). Wrong oil, your risk.

You will not cook 15W40 oil in the CRD. It is s diesel oil and works fine in Diesel engines. Worked fine in my Cummins and will work fine in the CRD. You CAN cook ANY oil in the CRD if you don't let the turbo cool down. If you want piece of mind, change the oil out.

wenied · **Joined:** Wed Dec 21, 2005 4:01 pm **Posts:** 107

OLD NAVY!!!
lol

Multi viscosity oils have polymers added to a light base (0W, 5W, 10W,15W, 20W), which prevent the oil from thinning as much as it warms up. At cold temperatures the polymers are coiled up and allow the oil to flow as their low numbers indicate. As the oil warms up, the polymers begin to unwind into long chains that prevent the oil from thinning as much as it normally would. The result is that at 100 degrees C, the oil has thinned only as much as the higher viscosity number indicates. Another way of looking at multi-vis oils is to think of a 20W-50 as a 20 weight oil that will not thin more than a 50 weight would when hot.

Therefore the 15W 40 will have the same "thickness" and flow characteristics as a 0W40 once it's up to temperature.

retmil46 · **Posted:** Fri Jan 13, 2006 12:24 pm

Reggie wrote:

You will not cook 15W40 oil in the CRD. It is s diesel oil and works fine in Diesel engines. Worked fine in my Cummins and will work fine in the CRD. You CAN cook ANY oil in the CRD if you don't let the turbo cool down. If you want piece of mind, change the oil out.

Exactly right. At the Freightliner Cleveland NC plant, the standard fill on all Detroit, Cat, Cummins, and Mercedes engines is 15W40 dino oil. We're talking the big 12 to 15 liter displacement 400 to 600 hp engines, with turbos as big around as your thigh, and in the case of the Cat C15 ACERT engines, twin sequential turbos. These rigs run more miles in 3 years than most of us end up driving in an entire lifetime.

The difference is, the people driving these rigs are trained how to operate them, ie follow proper cooldown procedure when shutting down at the end of the day, or have an automatic cooldown timer incorporated into the engine controls. At 150 grand per vehicle, you can be darn sure the companies buying them want to protect their investment.

With the CRD, how many owners, other than those on this list, even know there's a cooldown table in the owners manual? For that matter, I bet there's a few owners that haven't even cracked open the owners manual!

While there might be other advantages to using synthetic oil in this beast, I'd also wager than when it comes to POV's DC knew they would be dealing with a certain percentage of village idiots, and specing synthetic oil was in part their way of playing CYA.

I'd also wager that in the instance of the cooked turbo with dino oil, the owner had no clue concerning turbo cooldown.

oldnavy · **Posted:** Fri Jan 13, 2006 5:19 pm

wenied wrote:

OLD NAVY!!!
lol

Multi viscosity oils have polymers added to a light base (0W, 5W, 10W,15W, 20W), which prevent the oil from thinning as much as it warms up. At cold temperatures the polymers are coiled up and allow the oil to flow as their low numbers indicate. As the oil warms up, the polymers begin to unwind into long chains that prevent the oil from thinning as much as it normally would. The result is that at 100 degrees C, the oil has thinned only as much as the higher viscosity number indicates. Another way of looking at multi-vis oils is to think of a 20W-50 as a 20 weight oil that will not thin more than a 50 weight would when hot.

Therefore the 15W 40 will have the same "thickness" and flow characteristics as a 0W40 once it's up to temperature.

Ok you are just kind of saying at the last sentence wrong. The 15w-40 oil will still be a 15w oil with flow characteristics of 15w at operating temperature and with all the heat and film strength characteristics of a 40 wt oil. The 40 just means this oil maintains the same flow rate as a 40w oil would at a certian temp. As temps climb 40w oil thins out and at some point in the temp scale it will be the same viscosity as the 15w oil depending on additives, as the temps go higher at some point the oil will start to thicken again before it starts to char or burn. In synthetic oils the film strength, or as usually refered to as high temp shear strength, can be engineered to be higher or lower as needed reguardless of weight of oil like 10w-30 or 0w-40 or 5w-40, that's why one 10w-30 oil may be ok for use in an engine where another 10w-30 or even a 5w-40 might not work in the same engine because of lack of high temp shear strength.

As with oil & cooldown Retmil46 is right on the money. The only real avantage to synthetic oil is tempertature (cold & hot) and that the oil never wears out only the additive package. It's a lot easier to do CYA with a synthetic oil from mfg stand point.

Bonehead · **Posted:** Fri Jan 13, 2006 10:06 pm

alljeep wrote:

The turbo requires synthetic oil to lubricate it's bearings. Change it immediately or you will probably burn it out.

Now thats funny..............I need to tell all the turbos on the Cats,Cummins,Detroits and Powerstrokes I had over the last 15yrs, that the should have died instead of running strong for hundred of thousands of miles each like they did. :lol:

The biggest reason for synthetic oil is to make cold weather start up easier and quieter.

retmil46 · **Posted:** Sat Jan 14, 2006 1:15 am

If you think it's bad having to pop for 7 quarts of Mobil 1 for a CRD, imagine what it would cost if you had to put synthetic in one of the 18 wheelers, when one of those 15 liter Cats takes 8 GALLONS!!!!! :shock:

Multiply 8 gallons by 210 trucks out the door EACH DAY, and you get a real good idea why the big rigs still use dino engine oil.

In the trannys and differentials, nearly all those have switched over to synthetic. I'd love to get some of that Roadmaster 75W90 EP Gear Oil, 500,000 mile oil change interval! :shock:

oldnavy · **Posted:** Sat Jan 14, 2006 8:15 am

Actually there are quite a few using synthetic oil (Delvac 1 is main choice) and with by-pass filters and top off's running 100,000 mile plus oil changes the last 5 to 10 years. There are some owner/operators that have started doing it also. I was at the local truck center back before I sold my MB diesel, and talked with a guy that was having his big twin turbo Cat's oil changed and he had 130,000 on that oil change and he was also having the coolant changed if I remember. How we got to talking was I saw him looking my '83 MB over, he had an '84 300 D and we got to talking about oil for some reason. His MB had 325,000 miles with Rotella non sysnthetic oil and was wondering about any adverse effect to switching to Delvac 1 like he used in his Cat. Told him I was using D1 in the MB with no ill effects.

retmil46 · **Posted:** Sat Jan 14, 2006 12:27 pm

oldnavy wrote:

Actually there are quite a few using synthetic oil (Delvac 1 is main choice) and with by-pass filters and top off's running 100,000 mile plus oil changes the last 5 to 10 years. There are some owner/operators that have started doing it also. I was at the local truck center back before I sold my MB diesel, and talked with a guy that was having his big twin turbo Cat's oil changed and he had 130,000 on that oil change and he was also having the coolant changed if I remember. How we got to talking was I saw him looking my '83 MB over, he had an '84 300 D and we got to talking about oil for some reason. His MB had 325,000 miles with Rotella non sysnthetic oil and was wondering about any adverse effect to switching to Delvac 1 like he used in his Cat. Told him I was using D1 in the MB with no ill effects.

True, just like POV's, once the customer takes delivery of one of those rigs, it's their call as to what brand and type of oil they run in it. They can, when they order the truck from Freightliner, spec whatever type of oil they desire as initial fill, what we call a D-build or Deviation build or Per Serial. But from what I've seen, 99% of the time the initial fill is 15w40 dino.

Point is, the dino oil does meet the manufacturers specs for these engines, or we wouldn't be putting it in there to begin with. Think JB Hunt and Penske would be buying trucks from us if we put in oil that DIDN'T meet the warranty and operating specs? They would be raising 15 different types of Hades, and we wouldn't be able to give these trucks away.

By using dino instead of synthetic, it also holds down our operating and build costs, helping hold down purchase price for the customer and helping our bottom line. From just this one plant, we're pumping out 210 trucks per day times 5 or 6 days per week times 50 weeks per year equals one heck of a lot of trucks! Even a penny's difference in the price of a part can really add up.

And as a side note, the 15W40 oil we use has a minimum API rating of CI-4.

oldnavy · **Posted:** Sat Jan 14, 2006 1:17 pm

What's the RPM range of the new Cat twin turbo V8 anyway, I have looked the engines over but never looked at the gages or ask anyone. I remember the days when the high rev's were 2800 range with some in 3200 max RPM range, with most being non turbo engines. I don't think I ever saw a turbo diesel OTR rig until mid 70's, I'm not sure but I think the first turbo diesel I saw a Peterbuilt truck and it was a V8 and I think it was either Cat or MB engine.

As for as the bean counters go, those guys can really be a PIA. It's the same reason that OEM tires are generally the cheapest in the brand line. Man think how much D/C saves with the bottom line GoodYears.

retmil46 · **Posted:** Sat Jan 14, 2006 2:34 pm

All the engines we put in, Detroit, Cat, Cummins, and Mercedes, are in-line 6 cylinder turbos. The basic Century class truck was designed around a Detroit Series 60 engine as being standard.

The Cat C15 ACERT engines, in-line 6 cylinder with sequential twin turbos, if i remember correctly is rated 600 hp or better at around 2200 to 2500 rpm, and around 1500 ft/lbs torque at 1200 rpm. Been a while since I looked at the specs, so I could be off a ways. but from looking at the specs last time I worked the engine line, the Cat C15's were the hp and torque monsters of the group.

The standard tach installed on all the trucks only goes up to 3000 rpm max. These particular engines were designed for low end grunt, even for a diesel, to get a 80,000 lb semi moving. Low axle gearing (3.3 or 3.7 most common) and multispeed trannys to get them up to highway speed.

The specs on engines for individual trucks can vary somewhat. Wth all of them being ECM controlled now, they can program the hp and torque curves of the engine to more closely match the other equipment on the truck.

oldnavy · **Posted:** Sat Jan 14, 2006 3:38 pm

I remember the IHC's I-6 non turbo with a 2500 rpm tach that I got to drive a couple of times. The smallest hill was a killer, but in the mid '70's a Peterbuilt could do 100+ with 40,000 lb load and when empty they could out run most family sedans from 60 mph roll-on if dead heading or light loaded. I had a pair those Peterbuilts out run me one time in summer of '78 while I was driving my '76 Ford van to MO from NC to visit my folks. Seems my 300 CID I-6 topped out about 95 mph and those two trucks just walked off and left me. I had managed to just barly keep up with them coming over the Smokie's, because other rig's kept slowing them down. I was talking with them on the CB and they were headed back to CA, they said their trucks were built to run over the mountians out west with ease hauling big loads.

Oops. How bad is 15W-40 oil???

Who is online