Im wanting to go to a thinner oil for the cooler weather and Ive been running the Shell Rotella 5w-40 full synthetic in my 7.3 diesel for about 80k and based on my Blackstone reports its just a great oil. Wondering if I can run that in a 3FE. Is it too thin? If I don't run the 5w-40, Im gonna run 10w-40 so is there a big difference? I know a lot of people run 15w-40 in these and 20w-50, but I'm specifically looking for input on running 5w-40 in a 3FE. Any other oil nerds out there?
Thoughts on running Rotella 5w-40 in a 3FE?
- Thread starter studawg
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cwwfj60
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I wouldn't run 5w40, personally I run 20w50 but I'm in south Texas, 10w40 is the thinnest I would go, 15w40 even better. Plenty of people who don't know better take there cruisers into jiffy lube and get whatever the dork tells them (I used to be that dork....) alot of time it ends up being 10w30, I've even seen people run 5w30. I think this is a bad idea but all in all these trucks are tough and your oil choices won't kill anything. The heavier duty oils will protect your "tractor" engine much better. Perhaps your engine will struggle slightly on cold mornings but get up a few minutes earlier and let it warm up, no big deal. Ok I'm talking too much, stick with 10-15w40 rotella.
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- #3
Running 20w-50 now, and looking to gain any extra HP I can by running the thinnest oil possible. Ill probably be running 15w40 next summer, just wondering what I should go to for the colder months. I've never seen any talk about the 5w-40 around here so I wanted to poke around.
CaptHamster
TLCA #19645
I just changed from Mobil 1 15w-50 to Mobil 1 5w-40, and I'm in Los Angeles. Honestly I think 5w-40 should be totally fine, my biggest reason for the slightly thinner oil was for the winter, as I do take the Cruiser up to the snow all over the place, and would like the thinner oil for those cold temperatures. Remember, the owner's manual calls for 5w-30 if you expect to hit below freezing temps at any point, and I'll bet a good chunk of 3FE's on the road run mainly 5w-30.
Honestly the bigger number is the one I'm more concerned about anyway, as I care more about high temp performance as opposed to lower temps. Plus Mobil 1's 5w-40 has just as much zinc ppm as their 15w-50, which is good for our old flat tappet motors. I plan on running this oil until high summer temps start to kick back in, then it's back to 15w-50.
Honestly the bigger number is the one I'm more concerned about anyway, as I care more about high temp performance as opposed to lower temps. Plus Mobil 1's 5w-40 has just as much zinc ppm as their 15w-50, which is good for our old flat tappet motors. I plan on running this oil until high summer temps start to kick back in, then it's back to 15w-50.
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CaptHamster
TLCA #19645
Yes, that one exactly. I got it at O'Reilly for around $30 a gallon.
Ive been using this stuff for over 20 yrs. Very expensive!
Consistent 15 mpg (fwy).
Using regular ole 20w50 Dino oil is like driving with the e-brake on compared to this stuff.
Castrol Edge 5w-50 high zinc oil | Passenger Car Motor Oil (PCMO) - Gasoline Cars/Pickups/Vans/SUVs | Bob Is The Oil Guy
Consistent 15 mpg (fwy).
Using regular ole 20w50 Dino oil is like driving with the e-brake on compared to this stuff.
Castrol Edge 5w-50 high zinc oil | Passenger Car Motor Oil (PCMO) - Gasoline Cars/Pickups/Vans/SUVs | Bob Is The Oil Guy
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- #8
10-4, thanks, any idea on the zinc count in that compared to the Rotella 5w-40? More, less, about the same?
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- #9
Ha! This is exactly what I suspected. thx for that
CaptHamster
TLCA #19645
Mobil 1 Oil Chart
^This link has a chart with zinc levels for Mobil 1 oils. The 5w-40 has 1250ppm of zinc according to that chart, I'm sure the Rotella is similar. I usually run half a small bottle of zinc additive with each oil change as well.
^This link has a chart with zinc levels for Mobil 1 oils. The 5w-40 has 1250ppm of zinc according to that chart, I'm sure the Rotella is similar. I usually run half a small bottle of zinc additive with each oil change as well.
FWIW, I slowly migrated to thicker oils as the leaks got worse, all the way out to a 15W40. Then, as the leaks were fixed and carbon blocking the valve seats got removed, moved to the thin 5W40. This was over many years and many many miles. Finding places to coax a bit more umph out of these motors is tough, lighter oil is a pretty safe spot to get some though. Keep it fresh no matter what you use is the bigger truth.
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15w-40 and 5w-40 are the same in Florida...
You know the first number is the temperature at which the viscosity is affected right?
The second number is the viscosity at operating temperature.
For example, 10w-50 is thicker then 0w-30 in a warm climate.
The lower number is the weight of the oil at start-up. The second, higher number is the minimum intended weight achieved after warm up.
warm up temp is somewhere 100~120 degrees. If you're in a warm enough climate a straight 30 weight is a better engine protector.
Multi-vis oils contain viscosity enhancers. Viscosity enhancing chemicals do not add to lubricity of oils. The greater the viscosity range
the more enhancers in the oils so technically have less pure oil per volume. Multi vis oils were designed strictly to aid in cold weather starts. Single grade oils provide more corrosion resistance because they cling better to parts. Synthetics have higher lubricity but because of their lower viscosity at room temps tend to strip off internal parts faster.
Semi synthetics were the attempt to bring the superior lubricity of synthetics together with the superior corrosion resistance and cleansing
properties of pure oils together.
warm up temp is somewhere 100~120 degrees. If you're in a warm enough climate a straight 30 weight is a better engine protector.
Multi-vis oils contain viscosity enhancers. Viscosity enhancing chemicals do not add to lubricity of oils. The greater the viscosity range
the more enhancers in the oils so technically have less pure oil per volume. Multi vis oils were designed strictly to aid in cold weather starts. Single grade oils provide more corrosion resistance because they cling better to parts. Synthetics have higher lubricity but because of their lower viscosity at room temps tend to strip off internal parts faster.
Semi synthetics were the attempt to bring the superior lubricity of synthetics together with the superior corrosion resistance and cleansing
properties of pure oils together.
cwwfj60
Supporting Vendor
This is interesting regarding viscosity enhancers, didn't ever consider it replaces "pure oil". This seems like a solid argument for our engines, especially in warmer climates. and makes the case for a smaller viscosity range. I'll have to look into this more....
The other thing that gets erroneously thrown around is that the additives on the shelf will actually make the oil better. All oils have additive packages from the manufacturer. Things like ZDDP are added as wear protection from the factory but they can also be used hide deficiencies
in lower quality oils so having a low quality oil with a high zddp level may not actually protect your engine as well as a premium oil with a lower
zddp level. There are many anti oxidizing, detergent and anti wear agents in motor oils. Not all manufacturers use the same recipe and some chemicals are actually counter active with others so unless you're sure that a particular bottle of oil enhancer is good with the chemistry of the brand you run, you're better off just running a high grade by itself. I suppose the safe way is contact the oil manufacturer and ask if their product is compatible with something you want to add
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- #18
Yeah Im really not into adding anything to my oil, looking for an oil that meets all my needs from the get-go. Hopefully the M1 10w-40 HM is a good one for this engine even though it is maybe a little on the low side as far as zinc at 1100 ppm.
800 is actually more typical in today's oils but that number doesn't always completely represent the anti wear qualities since other
chemistry factors are involves. Rotella has always been considered a premium oil so that alone would probably out perform
a cheap brand with whatever additives you could possibly add
chemistry factors are involves. Rotella has always been considered a premium oil so that alone would probably out perform
a cheap brand with whatever additives you could possibly add
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- #20
Yeah I love the Rotella T6, but I went with the M1 10w40 High Mileage, I heard the high mileage version has some extra stuff thats supposed to swell up the old seals or something. Figured that can't hurt. Not sure if the T6 has anything like that in it.
