Sorry to start up this debate again, but I am due for an oil change and would like to be set straight.

Previous owner did all of the service through the local Rover dealer.
The last oil change shows this as the oil used - LRNAOIL 15W40 OIL

No brand, nothing. I assume it was not synthetic.
I found 2 previous service records where Castrol Syntec 5W40 was used and then records back to the LRNAOIL 15W40 from the dealer.

Rotella.

Seen a lot on here and did a little of my own research. Obviously that did not go so well as here I am looking for answers......

Is this supposed to be for diesels?

I'm not a chemist and I do not know the differences between oil designed for gasoline engines vs diesel. The more I search the more i read about detergents and how the added detergents can clean a gas motor...? How different properties are better for lifters etc,etc,etc....

My local Canadian Tire Store has these two offerings of Rotella,
Rotella T Diesel Motor Oil 15w 40

Shell Rotella T Synthetic Diesel Motor Oil, 5W40

Last oil change would have been at the dealer (LRNAOIL 15W40) non synthetic.
Which oil should I put in my Disco (2004) and how does this Rotella do what regular gas designated oil does not?

Why is it good for my 4.6 Discovery but not too much out there for use in other vehicles?

Thanks for your help and again, sorry to stir up the debate.

 

Here we go again.

Alot of guys will tell you to use rotella 15w40.
A few of us (5% of us) will tell you that 5w40 is prefectly fine.

Personally, i feel like this is on of the most over asked questions on here. Its like asking which brand of gas do you like using?

 

its your choise do you want synthetic or Dino oil? only you can make that call.

 

Either of the Rotella's are great oils, I would say go with the 15/40. The 2 other most important things are the filter and the duration between oil changes.
Never go over 5000 miles between changes and use a better then average filter, larger filter like the Mobil1-301 or the K&N3001 for much better protection.

 

What Mike said. Rotella also has good heat protection which I think might provide a little( a little) insurance for that not so lucky day where you might overheat.

 

Since you are in BC I would use the T6 5w40

 

I bought a Discovery I from brand new. Used Mobil 1 synthetic in this engine for many years.

My feeling now is that the synthetic did not do the Discovery I any favors.
Way too thin.

Now that the Discovery I has about 162,000 miles on it, I put in Rotella or this other semi synthetic stuff which is custom mixed by a small operation that sells at the autoparts store.

I usually run 15w/40 or 20w/50 in the summer if I can find it.
My reasons are:

The engine is well worn and out of tolerance.
The thicker oil (and non synthetic) will probably cause better oil pressure and protect the parts which are over clearance and over tolerance by providing an "oil cushion".

I am sure the main bearings on the Discovery I are too loose and need replaced.

-----
The Discovery II engine - the short block is nearly the same as the Discovery I.

I would put in thick oil if your miles are really high.

The linage of these engines is from 1960's Buick design. The Discovery II
is the last of this great linage. Great? Well, yes, until a head gasket blows or a liner slips or the oil pump quits. Then it is "great scot"!

 

Land
Rover
North
America
O
I
L

In other words Land Rover motor oil.
Because of where you live, 5w-40, 15w-40 will be fine for the summer, as would the 5w-40 for where you live.

 

Thanks for all of the tips.

I ended up going with the Mobil1-301 filter and Rotella 15w40.

It was the weight the dealer put in last time. Here in southern BC (right on the border) it is very seldom below 32 / 44°Fahrenheit (0 / 8°Celsius) in our coldest month (January) and I figured the same weight with the Rotella everyone seems to be believing in, I should be in good shape.

I seem to have noticed a slight tick coming from the engine inside the drivers side fender - only when at operating temp.

I hadn't noticed it before but I suppose I might be paying more attention to it now. Any thoughts?

The truck is now up to 75,000kms (46000 miles).

Thanks again for the input everyone.

 

some say (me included) that the ticking goes away with the 15w-40.