Very small construction fleet. What oil would YOU use?

Feb 11, 2021
Hello, newly minted member here.

I own a small wrecking company and I'm trying to decide on an engine oil for the diesels, as part of an effort to create a robust (i.e. foolproof) maintenance program. I'm based in New England.

The diesel "fleet":
(2) newer 6.7l powerstroke superduties. One is an F350 that is used variously as a daily driver/sales vehicle and regularly tows between 5k and 10k lb. It might spend a week hitched to a gooseneck dump trailer, during which time it's expected to start, haul a load real quick, and come back in the dead of winter. It goes to landfills a lot and sees a lot of dust. The other truck is an F550 packed with tools, fuel tank, etc. It doesn't typically tow, and is used simply to drive tools to a job site, where it stays all day.
(1) 2002 Isuzu npr diesel. Dusty tow pig, attached at the hip to a dump trailer.
(1) New-to-me 2002 cat 3126 motor in a 1995 road tractor. I haven't done much with this truck yet, but I expect to be grossing about 40k lb typically. No short trips. Hauling clean equipment, so not especially dusty.
(1) Kubota V1505 powered telescoping forklift. Enormous amounts of dust. Lots of idling. Lots of cold starts. Depending on the weather, I'll either let it idle for hours with intermittent use sprinkled in there or I will start it as needed, perhaps ten times a day. Sometimes - whether for security reasons or out of respect for neighbors- idling is not an option, so it will get started, then immediately move a big load, then shut down again. We're talking as little as two minutes of work for the machine in some cases.

I currently have Rotella T6 5w40 in everything but the cat motor (which has the previous owners oil still). I like the cold start snappiness of the 5w40, but it doesn't come cheap. And regarding OCIs and getting more out of it, I feel like dumping oil at 5k mi is more intuitive and will require less fussing around. In other words, I guess if I lived in Texas I would use 15w40 and dump it every 5k mi and be done with it. FWIW, I do my own preventative maintenance, in my shop.

I'd like to use the same oil in everything, to keep things simple. I'd really like to use the same spec year round, but we'll see. My biggest concern is my forklift getting beat to death from 15w40 in winter.

What would you do?

EDIT: typo
Think I would stick with Rotella-but T5 10W30 has very nearly the same cold flow numbers as T6 5W40, and will be a LOT cheaper to buy. Not sure about the Kubota & Cat, but there have been 6.7 Fords running 10W30 with good results.
If you're feeling lucky, this deal is almost unbelievable-
2 drums for a grand, free shipping included. It says 15W40 in the address, but it's actually 10W30.

Bulk 15w40 is what I would use in the trucks. For kubota I would use 5w40 as it doesn't get much use in the winter. Does all your equipment have block heaters? I installed tank type heaters on my farm equipment and I really like them.

I have a lot to consider, but at this point I'm definitely going to stick with 5w40 in the forklift, anyway.

No block heater in the kubota or the cat, but it's on my list to install one soon. However, I can't rely on plugging in all the time so must plan for the block being cold.

I used to run 15w40 in an old dump truck year round. It didn't like starting in January.

Thanks everyone.
Everything at my work gets this oil. They have many 6.7L ford Diesels with truck boxes instead of beds. A C15 Cat 475 hp,a 605 hp Cummins X15 and a few gasser Fords that say 5W-20.

All get this 10w -30. Oh we don't see many engine problems. We do see fuel issues and plugged air filters often. Every truck gets a complete service every 5 k which includes fuel filters and air filters.

No block heater in the kubota or the cat, but it's on my list to install one soon. However, I can't rely on plugging in all the time so must plan for the block being cold.

I used to run 15w40 in an old dump truck year round. It didn't like starting in January.

Exactly why I would stick with a 5W40. Having run diesels in the winter myself I know what its like trying to start one with 15W40 when its near or below zero.
There are 15w40 full synthetics also....

How far north in New England?

RI/CT... should do fine with 15w40... Maine... NH/VT.... stick with ANY 5w40 HDEO. I would take 15w40 and test cold start in all engines and selective choose which cranky engine gets the 5w40.

Ford has a great list of oils that should work with all your engines, whether you choose 5w40 or 15w40. I only recommend full synthetic HDEO and whatever brand you can buy in pails or even delivered barrels/totes... should contact local lube oil suppliers, otherwise you'll need shopping carts at malwart auto section. I don't recommend any 30 grade oil in a diesel engine that is worked.

Don't rule out conventional oils.... if budget doesn't allow a synthetic at those 5k intervals. Ford lists a few 10w40's conventional HDEO's too. And, for extreme cold, there are 0w40 HDEO's.
If you see T6 as expensive (I agree), most other name brands are in the same ballpark unless you want to chase rebates, like Mobil offers. A suggestion for you might be to go to a local farm supply store (TSC, Farm & Fleet etc...) and see what house brand they have in a 5W40 if cold starting is a concern. Here in Iowa Farm and Fleet offers their house brand for ~$25 for 2 gallons of semi synthetic 5W40. I personally use Mobil Super 1300 15W40 in my Cummins powered Ram. That being said I don't drive it if the day time high won't be above 0F. This week we had a few single digit days and the ole girl fired right up. After a few minutes of auto idle (~1,000RPM) with exhaust brake on she warms up some so I start to drive. I take it easy and it does just fine.

Just my $0.02

Your post was a bit confusing, you said that 5w-40 doesn't come cheap but also that you are "dumping" your oil at 5000 miles. 5000 is easy to remember but is probably costing you $$

In your place, wanting the same oil year 'round and (probably) wanting your expensive equipment to last, here is what I would do. It will require some record keeping and startup effort, but will save a lot in the long run:

Go with Schaeffer Oil. Get on their oil analysis plan and safely extend your intervals using their excellent diesel and hydraulic oils. Available in 55gal drums I believe and with the right rep your motor oil cost should be around $6.60 per quart and possibly lower. You can probably safely run your oil well over 10,000 miles, which makes it less expensive per mile than Rotella. 5w-40 or 15w-40 are available(as are 10w-30s), depending on your temps and pan heater plan.

But don't take my word for it. There are numerous testimonials from various industries on Youtube. Some are running their oil in excess of 15,000 miles and cut their maintenance budget by more than half with less part failures.

If this is something you might entertain, BITOG member salesrep is a Schaeffer rep, or you can shoot me a PM and I'll be happy to give you the contact info for mine.
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I Run M1 0W-40 on all my non DPF diesels and the following gas engines

It performs well and I can find it easily on shelves.

Kubota-d722 gensets
Cat - 3126B motorhome
Cat C11 gensets
Honda 2K's, yamaha3K, Kohler 20 KW air cooled gennies
Dodge (viper engine) 505 v10 - 700HP
Brigs 9.5
Nissan 5.6