Can of worms - Oil Question

July 16, 2020, 05:36 AM

Tow vehicles - RV or Trucks

Time or Mileage on oil changes?

This year mileage is going to be about zilch. Start them and run for at least 30 minutes to get temp every month but not much use beyond that.

July 16, 2020, 06:44 AM

Canted Valve

Blackstone oil analysis. Once you establish a baseline you'll know what to do based on YOUR real world data going forward.

July 16, 2020, 07:08 AM

HS professor

We have two trucks with 8.1's and they both burn a bit of oil. One has 30k miles the other has 98k and they both run identical. I always change the oil at about 3000-3500 miles, maybe its a bit premature but oils cheap, replacing the trucks isn't.

July 16, 2020, 07:56 AM

BD104X

My theory is this: the "time or mileage" rule is for everyday cars because the assumption is that if you are not hitting the mileage interval then you must be doing short trips (little old lady just going to church & the market), which doesn't get the oil up to proper operating temp. On my diesel RV and my Corvette, I don't use them too often but when I do it's for a long trip so the oil gets up to temp and any moisture boils off. On those I change the oil when they hit the mileage and ignore the 'time' - oil isn't going bad just sitting in the pan.

I don't start anything and just let it idle, IMO that's a waste. I'm more afraid of generating moisture by starting it and then not having it burn off properly from being DRIVEN - getting thoroughly warmed and giving the PCV system enough time to remove it. When my motorhome isn't being used, its plugged into a battery maintainer and that's it.

This is just my common sense opinion but hey, that's what you asked for and it's worth exactly what you paid for it!

July 16, 2020, 09:13 AM

183N

quote:
Originally posted by BD104X:
My theory is this: the "time or mileage" rule is for everyday cars because the assumption is that if you are not hitting the mileage interval then you must be doing short trips (little old lady just going to church & the market), which doesn't get the oil up to proper operating temp. On my diesel RV and my Corvette, I don't use them too often but when I do it's for a long trip so the oil gets up to temp and any moisture boils off. On those I change the oil when they hit the mileage and ignore the 'time' - oil isn't going bad just sitting in the pan.

I don't start anything and just let it idle, IMO that's a waste. I'm more afraid of generating moisture by starting it and then not having it burn off properly from being DRIVEN - getting thoroughly warmed and giving the PCV system enough time to remove it. When my motorhome isn't being used, its plugged into a battery maintainer and that's it.

This is just my common sense opinion but hey, that's what you asked for and it's worth exactly what you paid for it!

This is my approach too. And also every time I start something I work it hard to get it hot.

July 16, 2020, 10:13 AM

TomR

I use synthetic oil and change it every 5ooo miles in all my vehicles.

I just purchased a 2018 Ram with a 6.7l. They recommend 15k between oil changes but I think I will stay with my 5k schedule (maybe up it to 7500). Not sure, never owned anything with a diesel engine before.

July 16, 2020, 10:25 AM

Canted Valve

quote:
They recommend 15k between oil changes but...

That plays into their cost of maintenance sales pitch. Beware.

I sent in a sample from my Grand Marquis @ 4000 mile and just short of 2 years. They suggested another 1000 miles before a change.

July 16, 2020, 10:44 AM

Lenny5160

It takes me about 2 years to hit the 10,000 miles in my toter, but I change it either right before winter storage (preferred) or right away in the Spring.

It’s a massive expense if there is an oil-related failure, so going a little overboard makes me feel better.

July 16, 2020, 11:56 AM

FootbrakeJim

Anyone who goes the full mileage interval recommended by the manufacturer is clueless, IMHO. The don't want your truck to last 200-300K miles, they want you back for a new one (or major service) shortly after the warranty has expired. And anyone who believes an oil can effectively do it's job beyond 10,000 miles is penny-wise and pound foolish. (Even 7K is ridiculous, IMHO).
To pay $70K+ for a new top-line truck, and then chintz out at spending $50-60 two or 3 times a year to keep clean oil in it?

(OK, perhaps not everyone can change their own oil these days, so maybe it costs double that at a dealer or service place).

July 16, 2020, 12:22 PM

chasracer

quote:
Originally posted by Tom Reyer:
I use synthetic oil and change it every 5ooo miles in all my vehicles.

I just purchased a 2018 Ram with a 6.7l. They recommend 15k between oil changes but I think I will stay with my 5k schedule (maybe up it to 7500). Not sure, never owned anything with a diesel engine before.

If it's planned to be around long-term, stick with the 5k. Just look up the prices on some of the replacement parts in that diesel.

July 16, 2020, 12:26 PM

chasracer

I'm usually going with a one year deal on the truck and RV. My RV is 12 years old and only has 24k on it so it never gets much mileage on the oil. And it's always had a good synthetic since new. The truck sometimes hits 5K but maybe just once over the last 5-6 years. This past year, it has 1200 on it.

July 16, 2020, 01:02 PM

markemark

quote:
Originally posted by FootbrakeJim:
Anyone who goes the full mileage interval recommended by the manufacturer is clueless, IMHO. The don't want your truck to last 200-300K miles, they want you back for a new one (or major service) shortly after the warranty has expired. And anyone who believes an oil can effectively do it's job beyond 10,000 miles is penny-wise and pound foolish. (Even 7K is ridiculous, IMHO).
To pay $70K+ for a new top-line truck, and then chintz out at spending $50-60 two or 3 times a year to keep clean oil in it? (OK, perhaps not everyone can change their own oil these days, so maybe it costs double that at a dealer or service place).

I agree with this. Oil and filter change every 3-4k miles for my Hemi Ram.

The factory oil change monitor system in this truck has gone as far as 8k miles before alerting for service which I do not follow.

Oil on sale and filter is less than $20 doing it myself.

My truck is at 160k now and engine still pulls strong towing the Appalachians.

July 16, 2020, 01:18 PM

Canted Valve

quote:
I'm usually going with a one year deal on the truck and RV.

Then why on earth did you ask? You were simply looking for someone to agree with you and thereby validate you are right.

quote:
Even 7K is ridiculous, IMHO

"IMHO". That's right, without supporting data, and oil analysis, it's an opinion. Based on what you "believe". You may be right or you may be wrong you don't really "know". Which it say it's your best guess.

July 16, 2020, 01:36 PM

Bucky

quote:
Originally posted by FootbrakeJim:
Anyone who goes the full mileage interval recommended by the manufacturer is clueless, IMHO. The don't want your truck to last 200-300K miles, they want you back for a new one (or major service) shortly after the warranty has expired. And anyone who believes an oil can effectively do it's job beyond 10,000 miles is penny-wise and pound foolish. (Even 7K is ridiculous, IMHO).
To pay $70K+ for a new top-line truck, and then chintz out at spending $50-60 two or 3 times a year to keep clean oil in it? (OK, perhaps not everyone can change their own oil these days, so maybe it costs double that at a dealer or service place).

Jim,
This is greatly dependent on a lot of variables. Engine stress. Length of usage each run. Idle time. We live a ways from our jobs, and have all highway driving. At 7500 or so it comes out looking like it went in. And we seldom get rid of a vehicle before 150k miles.

July 16, 2020, 02:02 PM

FootbrakeJim

quote:
Originally posted by Bucky:
This is greatly dependent on a lot of variables. Engine stress. Length of usage each run. Idle time. We live a ways from our jobs, and have all highway driving. At 7500 or so it comes out looking like it went in. And we seldom get rid of a vehicle before 150k miles.

I definitely agree with the variables being a huge factor. And yes, long highway drives with light loading are probably the perfect scenario for extended change intervals. I've never seen oil come out at 7500 that looked like it went in, so you've definitely got a keeper engine in your vehicle. (And definitely not a diesel!)

For those of us who choose not to use engine oil analysis, (which I'm guessing costs more than an oil change, although doing it once to get a baseline is not a bad idea, like CV said), my advice is change it at 5K miles or less, and then you KNOW the oil is good.
In ideal cases like yours, Bucky, not gonna say you're wrong. Now if you were pulling 10,000 Lbs for even 1,000 of those miles, I would recommend more frequent oil changes.
BTW, my (bad) assumption was we were talking about tow vehicles, not passenger cars.

July 16, 2020, 02:15 PM

chasracer

quote:
Originally posted by Canted Valve:
quote:
I'm usually going with a one year deal on the truck and RV.

Then why on earth did you ask? You were simply looking for someone to agree with you and thereby validate you are right.

Not looking for anyone agreeing with me, I simply asked because maybe I've been dumping absolutely good oil and filters for no reason. Maybe I am doing the wrong thing in firing up the RV and letting it sit for 30 minutes. As was mentioned and it's a good point, the oil isn't going bad just sitting in the pan. I wanted to hear what others have done in similar circumstances and yes, this year and maybe many more to come has been a real wrench in the mess to boot.

July 16, 2020, 03:12 PM

BD104X

My RV uses 16 quarts - even a semi-synthetic oil change with filter is over $100 in parts. The fact that you guys think an oil change should be $50 explains why you think it needs to be changed every 3,000 miles and can't believe it still looks good when it comes out. Don't get me wrong, I wouldn't go 10 or 15,000 miles on oil, but 3-4000 miles is ridiculous. I will never understand why racers (who as a group usually understand the value of buying good stuff) use regular oil and change it more often when synthetic oil performs better AND lasts longer. Every OEM manufacturer of performance cars recommends synthetic oil and extended intervals, yet some of you guys instantly revert back to 1950 when it comes to maintenance!
FWIW, in my race car I use full synthetic Amsoil in a 584" on alcohol and change the oil after 60 runs.

July 16, 2020, 03:33 PM

head gamez

quote:
Originally posted by FootbrakeJim:
Anyone who goes the full mileage interval recommended by the manufacturer is clueless, IMHO. The don't want your truck to last 200-300K miles, they want you back for a new one (or major service) shortly after the warranty has expired. And anyone who believes an oil can effectively do it's job beyond 10,000 miles is penny-wise and pound foolish. (Even 7K is ridiculous, IMHO).
To pay $70K+ for a new top-line truck, and then chintz out at spending $50-60 two or 3 times a year to keep clean oil in it? (OK, perhaps not everyone can change their own oil these days, so maybe it costs double that at a dealer or service place).

I know you are referring to trucks, RVs, etc (maybe), but Ive got a 2008 Honda Fit that I bought new that now has 315k miles on it and the oil gets changed when the maintenance light comes on. Still a daily driver, and still a road trip car. It is one of those cars that will be a one owner until it gets picked up for scrap, and it still looks and runs very good.

July 16, 2020, 07:33 PM

Bad News

quote:
Originally posted by Tom Reyer:
I use synthetic oil and change it every 5ooo miles in all my vehicles.

I just purchased a 2018 Ram with a 6.7l. They recommend 15k between oil changes but I think I will stay with my 5k schedule (maybe up it to 7500). Not sure, never owned anything with a diesel engine before.

Investigate installing a bypass filter on it. the small micron, like 2 will remove the majority of the soot from the oil. Most injectors are HUEI hydraulically driven, so clean oil will help extend the life. Clean oil sure wont hurt. I bought the FS 2500 years ago.

July 16, 2020, 09:52 PM

Bucky

quote:
Originally posted by Bad News:
quote:
Originally posted by Tom Reyer:
I use synthetic oil and change it every 5ooo miles in all my vehicles.

I just purchased a 2018 Ram with a 6.7l. They recommend 15k between oil changes but I think I will stay with my 5k schedule (maybe up it to 7500). Not sure, never owned anything with a diesel engine before.

Investigate installing a bypass filter on it. the small micron, like 2 will remove the majority of the soot from the oil. Most injectors are HUEI hydraulically driven, so clean oil will help extend the life. Clean oil sure wont hurt. I bought the FS 2500 years ago.

How much pressure drop is there across those small micron filters? My cat motorhome is a five gallon bucket every time.