Common Information For All Powerstroke Diesel Trucks

Cold Weather Prep for Powerstrokes

I am here today with Tom Brown, Certified Lube Specialist and Amsoil dealer. (We won’t hold that against him.) He has a very informative YouTube channel and website called

We are going into the cold season. Down here in the south, it hardly ever gets below freezing but the vast majority of these trucks are up north where it is extremely cold. We are going to talk about cold start situations and what is the best way to prepare for them. You guys who have had diesels for a while are familiar with most of this so it will be a good review for you. But if you are just getting into the diesel truck market some of this might be new for you.

Batteries and Electrical
Batteries are the number one issue we always have to take care of on our diesels as we head into winter. There are two batteries on these trucks that have to be the right batteries and healthy. Also, make sure you have good cables, clean connections, good starter, alternator charging correctly, and the belts driving that alternator are good. You can’t have squealing belts that are allowing the alternator to slip. The whole charging system has to be functioning perfectly in order to keep these batteries charged up.

Test the batteries at any auto parts chain. Test each battery unhooked from the other. Electricity travels in a circle, so if your grounds are corroded or spots where the electricity travels between the block and the frame, you have to check all those straps to make sure they exist and that they are not corroded.

Service Up to Date
Have you done an oil change in the correct interval? Are you using the correct fuel? Down here in the south we hardly ever get into a blended fuel situation, but you guys up north will start getting that pretty soon. We are filming this in October, 2016, you may already start to see blended fuel showing up at some of your fuel stations farther north. As we get into the dead of winter you will definitely see blended fuel or #1 diesel start showing up. You will have to make the decision of when to move into those.

Archoil AR9100 and AR6200
You know I am an Archoil fanatic. It funds Train-A-Vet. Buy some, you need it. The AR9100 oil additive and AR6200 fuel additive will do a tremendous amount in terms of keeping everything highly lubricated and clean. These are very important things. But AR6200 is not an anti-gel. As far as an anti-gel, I recommend Howes. Howes is the only company out there that has a guarantee that your fuel is not going to gel. It is pretty good stuff. We don’t use it much down here. But every now and then you have to have some of this around and it is good stuff to have.

What we are really here to talk about is oil and just how important selecting the correct viscosity is.

6.0 Liter
This chart came out of TSB 05-16.6 which Ford released some time ago. The big change they made was adding 15w40 basically at the entire temperature range for towing. We are all use to using 15w40 in the warmer temperatures but as you get to 30°F we are sitting at the freezing point and you ought to start thinking about possibly using a lower viscosity oil as that temperature starts to slide down. You will see 0w30, 5w30 and 5w40 are acceptable for Ford in the 6.0L as we get below freezing. As you start to get below -10°F, Ford also specifies that you must use a plug-in block heater for your engine as well.

Even at lower viscosity, oils start to thicken as the temperature drops. So when you go out there in the morning to start your truck, even if you have all the things on the checklist (batteries are good, connections are good, and everything is working well), that engine has got to start spinning over somewhere between 175 and 200 RPM before it will start. If that oil is too thick, the starter simply can’t overcome the friction of the oil and it can’t get enough revolutions going to allow the engine to start, especially with the HEUI injectors. You have to get RPM to get that high pressure pump to roll.

6.4 Liter
The 6.4L is a little different animal because it has a high pressure fuel system and intense computer control. Ford has started to allow 0w30 and 0w40 on a little bit broader range and same with 5w40. 5w40 covers almost the entire temperature range. If it is going to get colder than -20°F you need to drop down to a 0w30 or a 0w40 or you are going to have to run a block heater the whole time. You will notice 15w40 stops right at about 20°F. That is when you need to start thinking about coming down to a lower viscosity oil.

So basically the 6.4L is a tighter tolerance motor and because you don’t use the 6.4 oil to run a high pressure oil pump, they have changed the specs a good bit. The fact that 15w40 is acceptable only down to 20°F is kind of amazing. Ford is changing the spec on these for a couple of reasons. One is because their engine technology is changing; the other is the oil technology was changing during these periods. We are starting to see much more availability of 0w30, 0w40 and even 5w40 that will cover this entire range.

6.7 Liter
This oil viscosity chart is out of the 6.7L owner’s manual. 5w40, 0w30 and 0w40 cover the entire temperature range whereas on the 6.0 and 6.4 they were calling for you to stop using those oils when the temperature got very high. Now they are saying, you can run those lower rate oils all the way out. The 0w30 and 0w40 are more available, better and they can take the heat on the high end and they will still flow on the cold end. Also, Ford is trying to help you get better fuel economy.

Oil for DPF trucks has been reformulated. CJ-4 oil was brought in back in about 2007. They began to pull some of the additives and naturally occurring elements out of that oil because it was going to start plugging up the DPF. Diesels do burn a little bit of oil because there is such extreme compression. In December, 2016 we are going to see CK-4 and FA-4 hit the market. We are going to do another video on those as soon as those come out. There are no big alarming changes coming; it will just be the next evolution in diesel oils hitting the market.

So Tom has put together a couple of graphs that he will send you if you email him at or you can just go to his website and there is a “contact me” link right on there. This is what is very compelling about just exactly how much viscosity increases with the temperature drop. There is an inverse proportion of temperature versus viscosity. We are going to compare three different Amsoil oils (5w30 Heavy Duty Diesel Oil, full synthetic; 5w40 CJ-4; 15w40 marine diesel oil) and a Motorcraft oil 15w40 CJ-4.

Down here at the bottom on the far right corner of the chart, we are at 100°C or 212F°; this is your engine at full operating temperature. It really doesn’t matter what the outside temperature is because the thermostat on your engine is going to cause the engine to warm up to 100°C or 212F° regardless of the outside temperature. As we cool down in temperature, the lines go up reflecting that the viscosity is increasing or the oil is getting thicker.

At 40°C or 100°F, which is about the starting temperature for most oil specifications, you will notice even the 5w30, the lightest of these oils, is already 600% thicker at 100°F than it is at 212°F. As you continue to cool down to 0°C or 32°F, the lines are shooting up and the 15w40 conventional Motorcraft oil has thickened by 9,000%.

This measurement on the left of the chart is not thickening in the sense of going from a 50 weight or a 40 weight oil up to a 100 weight oil; we are using centistokes which is the scientific measurement of viscosity. You would have to convert those to actual SAE viscosities. What is important is the amount of change anywhere from 5,000% to 9,000% thicker just from 212°F down to 32°F.

At -40°C which is also -40°F (they cross over each other at that point), the 5w30 has thickened 211,000%. The conventional 15w40 has thickened 831,000% it is basically a block of frozen oil sitting in the bottom of your oil pan. That is why Ford tells you when you get below -10°F you have to use a plug in block heater because even if you could get this engine to start, you would destroy it almost immediately because there would be no oil available. All of the oil is basically frozen and the oil pump cannot move it. Starting it is actually the worst thing you could do unless you have it plugged in.

As we head into the winter, you really need to start thinking about what oil is in your engine right now. Is that the right oil as the temperature starts to drop? You don’t want to be that guy out there on that first cold morning and your truck won’t start. Take the time now to get ready for that. If you have any other question about anything we have talked about today, you can contact Tom If you have questions about lubrication issues in general, contact Tom. He would be glad to help you out.

We all know that diesels are much happier when it is warmer out, but when it gets real cold, you have to prepare for it. Check your batteries, have them checked individually, make sure your block heater, alternator, and all that stuff is up and working. You want to do this now while it is warm not out there freezing trying to fix your truck. Get your service done. Add Archoil and anti-gel and understand that the type and grade of oil that you run is absolutely crucial to success. Tom told me he has a customer in Flint, MI in a 7.3 with 200K+ miles with original injectors running the 5w30 heavy duty diesel Amsoil full synthetic and that is all he has ever run and it starts perfectly without even plugging it in. He is probably getting down to -10°F. If you have to operate your truck in cold weather (and I hate it for you), check out Tom’s website because he has a lot of interesting information on there that could be very helpful to you. ~Bill Hewitt

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