So i was talking to this guy who owns a Land Rover Mechanic shop, that's all he works on is Rovers. He says the best oil to use in my discovery engine is 20w50, I just wanted to hear what you guys thought about that. I'm currently using 10w40 full synthetic. He's reasoning is that once you get on the highway and drive long distance say more than 3 hours, the oil pretty much turns into water.

On a side note, i was at a salvage yard, and saw a arb brush guard that came off a 04 tacoma. Is there any chance that it could fit on a disco I. I asked them how much it was, but they said they'd have to talk to the boss about it. I've got a picture of what it looked like.

 

Just because a guy is a good mechanic does not mean he knows about oil. It would work in the summer, definitely not all that well in the winter. Your 10w40 syn is just fine as is any 40 wt. Oil viscosity depends on temperature not time and your temperature after 1 hour on the highway is the same after 3 hours so the oil will be the same viscosity.

 

The ARB would have different mounting points.

A 10w40 oil is as thick as a straight 40 weight oil once they get to operating temp, and flows as a 10 weight oil cold.
This will hold true for a 20w50 as well, so if your motor uses oil or has a lot of miles in the summer it would make sense to use 20w50 if its very hot where your at.

 

It is all about film strength. Original dino oil would break down. Not the stuff today. I run 10W30 in mine and I have almost 190K on the ticker. No leaks, no knocks, no burning. Some think you need to stick heavier oil in as the miles rack up. Not true. Run a good synthetic that will stand up to the added stress and you are fine. 20W50 is too thick and all you will do is hurt the engine.

 

Your oil weight should be based on where you live and the temp., not some ones opinion.
In Colorado, I run a 5W/30 in the winter and a 10W/40 in the summer. While living in a hotter area, Arizona, I only ran 20W/50.
Make sure to use a good filter like a K&N 3001 or a Mobil 1-301.

 

Sounds like i'll be sticking with the 10w40 synth. Thanks for y'alls imput.

 

Is it ok to run 5w30 in my Disco in the summer? Are there any advantages/disadvantages from running one weight versus another? Thanks!

 

Check your owners manual. From your name, I would guess Alabama, and you can run up to 10W40 in the summer. What brand of oil are you running? Synthetic?

 

It depends on the model year. My 2002 owners manual says anywhere from 5w30 to 5w40 to 10w40 SJ (which is an old spec). The 2004 (different engine) manual says to "use Castrol 10W/40 engine oil meeting specification ACEA A2. If Castrol 10W/40 is not available, Castrol 10W/30 can be used".

Personally for these engines I use a full synthetic heavy duty engine oil in 5w40 or a 15w40 conventional HDEO. These oils are made with higher additive levels (both wear and detergents) and can handle most anything these engines can throw at them. This winter I am trying out mobil 1 0w40 and will get a used oil analysis to see how it stands up. Synthetic 5w30 oils are generally OK but generally the SM rated oils are energy conserving oils and have additive levels that are lower than previous generations and can shear down to 20wt oil. Some good commonly available 30wts are mobil 5w30 EP, 10w30 EP and Castrol Syntec 0w30 (so called German Castrol because it is made in germany and is a near 40 wt oil).

My truck was run on steady diet of bulk conventional 5w30 up until around 80,000 miles (I bought it at 56k did not know any better) changed at reasonable intervals for today's oils 3-5k miles and it was heavily varnished inside, totally black at 95k when I did my head gaskets (after switching to a 5w30 bulk synthetic). Lifters and cam wear were fine though and I could still see the factory cross hatching on the cylinder sleeves and valves were OK but it was black inside (no sludge). This was after overheating once and pretty much sounding like a diesel. After learning of oil and switching to a synthetic HDEO and doing a couple flushes and short cleaning OCIs my engine is much cleaner (after dropping the oil pan and front cover) at 115k and is silent now with no lifter noise at startup.

A very thick oil can be used for consumption problems or to keep a dying engine going for another year. Mobil 1 15w50 is good summer oil too and is nearly a 40wt.

 

In the winter i live in Michigan, and in the summer I'm down in Alabama/Georiga. My vehicle gets the extremes of both worlds LOL. Currently i'm running Castrol 5w30 Synthetic w/ a Bosch oil filter, and in the summer i ran Castrol 10w40 Synthetic w/ Bosch oil filter.