I'm the 2nd owner (for about 3 months) of an '03 disco, with 72k miles on it. She's been pretty much trouble free. I use Royal Purple synthetic 10-30 and run K&N 3001 oil filter. No off-roading; just my everyday car. As for climate, I live just outside of Boston. I've performed a throttle clean and sea foam when I got her back in Feb.

I read here on the forum that running 20-50 oil in summer and then 10-40 in winter should be fine. Another poster suggested 40 anything is all anyone needs. Is 20-50 too thick of an oil for my Landy? I'll probably put 20k to 30k miles a year on the disco.

I'm only considering 20-50 because the engine runs hot and I'd like to make sure all her insides are nice and lubed.

Thanks,
Rob

 

20/50 is not to heavy, in less you are very cold like below freezing.

 

I ran 20/50 for 7 years in California and 4 years during the warn season here in Denver, works great.

 

I am going to switch to 20-50 this summer as well it gets hot in CC Philly. when you say she runs HOT, what do you mean. do you have a plug in temp gauge. have you addressed your coolant system, i.e. still running old dex-cool. have you swapped out to the soft spring thermostat. flushed the system etc.... I would make sure that you have looked at his as well. engine oil is not going to do all that much if the coolant.heating system is not up to par.

 

Rover manual says 10W30 approved for use up to 95F. So in Boston summer traffic that would be a out of range. People that run high dollar oil sometimes also increase their drain interval. Not a good idea on a old school engine design. 5000 is the max. A diesel rated oil will have more ZDDP which is helpful to the flat tappet engine design, this is not an exotic engine. The Shell Rotella is widely available, cheap, and does a good job cleaning the engine because diesel oils are formulated for soot control, particles stay in suspension better and get caught by the filter. I advise to run a jumbo filter so you will have extra oil capacity.

The heat is no joke. Rover decided we are too stupid to read an oil gauge, so there is not one. We are too stupid to watch a temperature gauge, so the computer geneates a signal to keep the gauge at 50% reading from abot 130-240F. You'll drive for months at 230F thinking everything is OK, while oil and the rest of the engine is slow roasted. Pix of engine under 50K, dealer oil change intervals. If you are running at 60 - 75% that is bad. A scanner, bluetooth adapter to smarty phone interface, or the Ultra Gauge can tell you the real coolant temps. A 180F stat will drop those to a more reasonable level. Older radiators that have not been regularly flushed (2-3 years, not ten years) will become sludged, no fix other than replace. If rad is sludged, temps on the fins top to bottom will have a difference of more than 10F, truck warm, engine off. Viscous clutch has to be working, electric fan has to work (212F), not be siezed, blown fuse, etc. Coolant cap shoud be swapped if you never have. Dexcool makes mud/sludge, needs to be flushed out and replaced with green 50/50 premixed.

 

Everyone has their own opinions about oil, but I would just go to Walmart and buy Shell Rotella 15w-40 dino oil at $12/gal. and skip the synthetic. Just change it every 3-4k miles.

 

I do not nor have I ever run synthetic. I use rotella 15w-40 year round. My thoughts on moving to 20w-50 is that in the city when it is 95 with 98% humidity and I am moving at a pace of never more than 20-25 and it is stop and go traffic the heavier weight cannot HURT. If i am planning a longer trip I would switch back to the rotella but for the short runs thru and around the city I feel the 20w 50 will give a tad more protection is it vodoo thinking, maybe but it certainly will NOT hurt anything.