Okay, I know everyone has their own theories on which oil to use and why, but I would like to know which one best fits my situation. Yes, I do use the synthetics, Ive only used mobile1 10w40 since I bought it.
First of all I put a ton of miles on my land rover every month... between 2,100 and 2,500 miles a month. I am in Northern Illinois where the temps can get below zero, and over 100 depending on the season. I stay on the paved roads 99% of the time, and my driving is a mix of highway and city driving. Should I stick with the mobile1 10w-40, or use something else. I'll be changing it either early this coming week at about 6,500 miles or next weekend at just under 7,000 miles. Oil is always still good, and no burnt smell, and only a couple drips between changes.

Thanks for any suggestions
Scott

 

The answer is no, Mobil 1 is no longer the oil of choice as it used to be. A lot of people are switching over to Shell Rotella 15W/40 because of the additives it has that can better protect our valve train from wear. Also consider using something like the Mobil1-301 oil filter for it larger size and better filter qualities.
Might also want to cut your oil changed back to somewhere between 5000 and 6000 miles.

 

Life is tough inside a Buick engine designed for the 1960's, and 5000 miles between changes is better, IMHO. Don't remember people doing long drain intervals back then, maybe they were on to something. Certainly not the 7500.

 

Thanks Mike, the Mobile1-301 is what I have been using for the filter, is the oil you mentioned what I should use year round, or should I switch it up for summer/winter driving considering the mileage i put on and the climate I am in? My last oil change was right at 5000 miles and was almost as clean as the new oil I put in...

BTW thanks for your help last month about the front drive shaft and wheel hub/bearing, its been a much smoother & quieter ride since then... I really appreciated the advice

 

15W40 is rated for use by Rover for 0 C to +55 C, in the winter you will need to switch. See workshop manual under Lubicants, Fluids, and Capacities.

 

Use the 15w-40 year round if you are driving that much.
Mobil 1 is crap oil now.
Their oil filters are good although I will not pay $12 for a oil filter.
But here is what I would do if I were you, use the Mobil 1 filter and the Rotella 15w-40, change it at 5,000 miles and take a oil sample and send it in to get analyzed.
They will then tell you how long you can go on a single oil change.
With that oil and filter I see no reason you cant go 10,000 miles between oil changes, but you MUST have a service oil sample taken first.

 

Savanah, True, but then again, I don't believe the they were running synthetics in the engines back in the 60's. Off hand I think the manual says 7000 or 7500 miles for the DII, I have never gone a mile over 7000 between changes, or what any of my vehicles recommend, I tried to get it changed sooner this time, but its not always possible with locations and times that I work, Like I said, last time was right at 5000, and previously was 5000-6000 range

 

well It sounds like the Shell Rotella 15w-40 and Mobile1-301 are what I will use, I'll try Spikes idea of testing the oil after 5000 miles (just for piece of mind), but seriously doubt I'll go the full 10,000 miles if they say its good to last that long... Let me make sure of this, do the oil change and filter, at about 5k take sample to be analyzed, and wait for results, correct?

 

Yes, that is correct.
You can buy the oil sample kits at NAPA, AutoZone, etc.
They cost like $30 but that includes shipping.
Just follow their instructions, usually it is drive until fully warmed up, start the oil draining and take a sample half way though the draining process.
Send it in.
When I drove truck this was common practice to determine the longest you could go between oil changes, when you drive 2,000 miles a week or more (and you take 24qts of oil) you cant be changing your oil every 3,000 miles.
And yes, LR says once a year or every 7500 miles, whichever is sooner.

 

Okay, I went to O'rileys auto parts, they carry the rotella in the 15w-40, but it's not synthetic, and the synthetic they do have is not the 15w-40,their warehouse doesn't have it either... If I get the 15w-40 rotella they have it is regular oil, so does this mean I need to flush out my oil to chance to conventional oil, or should I try other places like autozone, napa, advanced auto parts?