use mobil one i dont know why some of these guys are running diesal oil in their trucks but i personally think its way to thick for our motors unless u live in extremly hot climate mobil one 10 30 or 5 30 is the way to go. and i wouldnt run anything else in my own trucks

 

You should maybe study up on oils before you make generalizations like that. Hot climate should have no bearing on oil wt used 100F is nothing compared to the temps inside your cylinders. We run 40 wt HDEO because they are better oils with better basestocks and higher levels of antiwear additives. Modern oils are not formulated with flat tappet, fuel diluting, overheating ancient technology engines in mind. My manual actually says I can use anything from 5w30 to 15w40. I believe in 2003-2004 they smartened up and went to castrol 10w40. Using a 5w40 synthetic HDEO is a no brainer especially with how cheap it can be had.

 

My owners manual says anything from 5w-30 to 20w-60 can be used depending on climate with 10w-40 being the "recommended" oil viscosity.
Now keep i mind that the is NO DIFFERENCE between the internals from a '89 Disco V8 to a '04 Disco V8, SAME ENGINE.
So if it is safe to run 20w-60 in my '97 would not the same be true for a '04?

Start here on your research.
http://www.carbibles.com/engineoil_bible.html#viscosity

This explains how the get the oil viscosity ratings.
http://www.carbibles.com/viscosity.html

 

You should maybe study up on oils before you make generalizations like that. Hot climate should have no bearing on oil wt used 100F is nothing compared to the temps inside your cylinders. We run 40 wt HDEO because they are better oils with better basestocks and higher levels of antiwear additives. Modern oils are not formulated with flat tappet, fuel diluting, overheating ancient technology engines in mind. My manual actually says I can use anything from 5w30 to 15w40. I believe in 2003-2004 they smartened up and went to castrol 10w40. Using a 5w40 synthetic HDEO is a no brainer especially with how cheap it can be had.

If you ever have the chance to speak to a Aussie disco owner ask what viscosity they use. Probably a 60wt. They will shake their head at the water (15w40) we put in our engines.

 

If I'm not mistaken, the shop manual sez' 20-40 is good down to 32deg. f.

I use 15-40 thru' the summer

10-40 in winter

luck,greg

 

http://www.aa1car.com/library/oil_viscosity.htm

Here is a flow chart.

 

Thanks for all the comments Im now thinking of going back to Synthetic even though I wont be able to have Land Rover do oil changes anymore due to their refusal to use synthetic.

 

^ They have synthetic on had, I think they use castrol syntech in the range rovers. They probably didn't let you buy any because they don't have qt sized, theirs are in 55 gallon jugs. The also probably dont' want to put it in because they don't want you to B!tch to them when/ if the seals leak. If you don't like doing the changes, just tell the advisor you know they may leak, and that you will not give them negative ratings on their surveys, and have them put in the synthetic.

 

Rotella 15W40 year round In all of our Rovers.. Works great.. High detergent and doesn't break down...

 

x2

Oh, by the way, Hi everybody! Miss me?