The correct engine oil???

[Fireyred]

Rang up Wilco Car Spares in Wellingborough to ask them how much there oil was for my Landrover 90 so I can do an oil change.

Required according to them, 7ltr's (6.8 to be exact) of 10w40?

Is that correct as i am sure put 15w40 in last time.

Cheers

 :)

PS She is up for sale too if anyone is interested pm me please

[TDi90]

10w40 or 15w40 is fine.
either doesnt really matter.
Rob

[Fireyred]

Take it that one is thicker than the other?

[Range Rover Blues]

The number is the viscosity, so higher is thicker.

There are 2 numbers becasue it's multigrade, when a 10w/40 is cold, it's as thick as an SAE10 oil (10 weight oil). when it's hot (100 degrees c or more) then it behaves like a 40 weight oil.

THAT DOES NOT MEAN IT GETS THICKER   it just doesn't get as thin as a monograde oil.

So the lower number, often the W (winter) number  is it's viscosity at startup, yo uneed a thin oil so that it'll move round fast and protect the engine as soon as it fires up.

With that in mind it's better to use a 10w/40 at this time of year and a 15/w40 in the summer.