Motor oil

[agdirect]

Our field techs. drive GMC 4x4 pickups and sometimes pull heavy trailers in 100+ temps. The owners manual recomends SAE 5-30 motor oil. What is the top temp. fpr this oil. I have been using 10-40.

 

[Andyrooz]

Firstly, what are the night time temperatures if the day times are 100+ ? Secondly, are you employing deisels as opposed to petrol? Thirdly, size of rig in total lbs weight? size of engine? capacity of oil sump? Does it have an oil cooler as standard equipment? Does low range gear ever get used and if so by what ratio over the day?
If a cooler is fitted, is it seperate from the cooling radiator or is it built in?

I would like to hear from you, Ta very much.

I run a Landrover 130 dual cab ute, kerb weight ready for work is 7275lbs plus the trailer at 4630lbs and do not have a problem at all towing around Australia with a 4 cyl' 186 cubic inch turbo deisel. Regards for now Andyrooz

 

[agdirect]

The night temps are in the 80,s F.. We use gas engines. The weight for our trucks are close to what you have. The trailer weight is about 5000 pounds.