Newer engines are machined to tighter specifications than older motors. Newer motors require a lighter grade oil for lubrication like a 5 or 10 weight. The 5 or 10 weight can move through the engine and get to the places that need lubrication better than a heavier grade of oil. A 10-40 grade moves through the engine like a 10 weight oil with the ptotection of a 40 weight oil. If you put a 30 weight oil in your engine, it will not move through your engine as easily and when it does get to the parts that need lubrication, it does not do as good of a job.
5W30 And it is written on the oil cap.
It depends on the ambient temprature
15 40 wight oil
The 1964 GMC v6 truck uses 5.5 quarts of oil or 6 if that of the oil filter is included.
one quart 10w40 four stroke motorcycle oil. do not use car or truck oil. 10w40 4 stroke oil is car & truck oil which are also 4 stroke engines. You can use the very same oil you use in your car and truck as long as you use the correct weight which is 10w30 and not 10w40. There is no difference in so-called motorcycle oil and car or truck oil. I do however highly recommend you use full synthetic oil in any air cooled engine.
you can use 10w 30 or 10w40. doesnt matter that much. the weight relates to the thickness of the oil but you dont want it to thick because then it gums up.
SAE 10w30
That depends on what model of truck it is, and what motor it has in it.
90 W Gear oil
Yes, 90 weight oil is recommended.
Use the manufacture recommended weight and switch to a High Mileage oil.
The Ford motor company recommends you use 10W-30 weight motor oil in the 1998 Ford F1 50 truck. A heavier weight motor oil can be used in extreme climates.