Originally Posted by Brian Sanders
Hello just got a 1991 Nissan pickup. What weight oil goes into it (think 5w30) and should I use regular or synthetic oil? Only has 156k miles on it and it’s the original engine. Thank you in advance.
Those Hardbody's are Great Truck's. I had a '93 that I bought new and drove it for 20 year's. It was still running Smooth and Quiet with 175K mile's when I sold it, after getting a new '13 Frontier.
The Fellow I sold the '93 to, didn't want the Service Manual,, so I looked up the Engine Oil Viscosity Chart. Nissan say's that the preferred oil viscosity is 5w30, which cover's the whole Temperature Band. However I live down in the Deep South and used 10w40. According to the Viscosity Chart 10w30 and 10w40 is good from 0 Deg F to over 100 F.
I personally wouldn't put Synthetic in it with 156K Mile's, unless you can verify with the previous owner that they used Full Synthetic in it. If the Previous Owner used regular dino oil; Putting Full Synthetic in it with 156K mile's, might cause it to start Leaking Oil. So far Nissan hasn't specified Synthetic for the Engine's that I've owned, so I use Regular Castrol GTX. In the New '13 I do use 5w30, simply cause it has such a High Cold Idle speed on Startup, otherwise I would be useing 10w30.
I would try to find an Owner's Manual for your Truck. Nissan Consumer Affair's might still have one. Also I would try to get a download or hardcopy of the Nissan Service Manual for your truck as well.
A list of all of the proper Fluids that Nissan Recommend's is in the Owners Manual as well as the Nissan Service Manual.
Those Hardbody's are Great Truck's,, and I hope that you enjoy your's. Sort of like a ThrowBack to yesteryear ie No Air Bag's, and all the unnecessary Electronic Stuff that they have now that we have to contend with fixing by reading code's and chaseing after sensor's that cause a Light to go on in the Dash. I still miss those Seal Beam Headlight's. I don't much like this New Headlight Bulb with a Plastic Len's that get's Cloudy as the year's roll by.