5w-40 Synthetic Diesel Oil. Anyone using it?

SD diesels were widely available in the US in the 1981-86 Datsun/Nissan 720 pickups, and in Canada through '87 in the D21 pickup.

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Joined: 9 years ago
Location: VancouverBC

5w-40 Synthetic Diesel Oil. Anyone using it?


Post by NeilPierce »

It's been hitting around zero degrees celsius where I live. Cold starts are extremely smokey and difficult. If I could plug the block heater in I would, but unfortunately it's not an option in the location that I have to park my truck. It sure runs great once it's going though.

Just wondering if anyone out there has found that using a 5w-40 synthetic oil has alleviated cold starting issues? Is it too light of an oil for these motors?

I've been running 15-40 diesel oil in this truck forever, but I can't keep smoking out my neighbors.

I'm going to bet money that someone will suggest getting my injectors looked at as far as spray pattern, but before I do that I just wanted to get some feedback on the oil idea.

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Location: Canada


Post by Nissan_Ranger »

I'm using (and have been for 8 years) 10w30 full synthetic oil. The engine starts readily without plug-in down to about -10C. It will start with more glowplug time and cranking down to about -20C. I don't use 15W40 in my engine as it is too heavy, causing usage.

I doubt your injectors are a problem. It's the 15W40 oil. My engine originally called for some weird weight I can't even recall. Oil technology has come a L O N G way since my engine was made and 10W30 synth puts the original dinosaur oil for this engine to shame... I've used Quaker State 'Q', Canadian Tire house brand full synth, and Walmart Tech 2000 (?) house brand full synth oil. They all work and my engine is in as good condition as when I first started using it over 150,000 kilometers ago.


The old 'six gun' was as popular as the cell phone in its time and just as annoying when it went off in the Theater.
Posts: 7
Joined: 9 years ago
Location: VancouverBC


Post by NeilPierce »

Good stuff. Sounds like it's time to switch.

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Location: Cochrane Alberta Canada


Post by plenzen »

I am using 5/40 Rotella in the winter and 15/40 in the summer. It uses a bit of the 5/40 on a long highway ride but only about 1/2 L in 5000 Kms. Starts a lot easier as well.
I switch to 5/40 end of Oct and back again in April.
Truck lived it's life in Vancouver BC and on 15/40.
When I brought it here it saw -25C to -30 C for the first time.
It did not like it that much.
The 5/40 helped a lot.

Retired Pauly
Problem with being retired is that you never get a day off.
1987 D21-J SD25 KC
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