At 80,000 miles switch to Synthetic?

Topic: At 80,000 miles switch to Synthetic? (Read 786 times) previous topic - next topic

At 80,000 miles switch to Synthetic?

January 10, 2017, 11:20:25 am

Our coach (Detroit Diesel 8.2 L V8) currently uses Rotello 15W-40 oil. Can I safely switch to synthetic?
Only 12 Qt capacity with filters.

Years ago I switched oils in my 454 Chev pickup to synthetic and then drove to Clearwater, FL. It had about 97,000 miles on the odometer. Within two weeks I was blowing oil smoke out the tailpipe and adding a quart every week, so I am cautious about switching.
Apparently the synthetic cleaned out the engine so well it leaked oil by seals & rings in the engine.

Re: At 80,000 miles switch to Synthetic?

Reply #1 – January 10, 2017, 11:33:21 am

White container rotella as I understand it is 50% synthetic already. Excellent oil.

Re: At 80,000 miles switch to Synthetic?

Reply #2 – January 10, 2017, 11:41:11 am

The synthetic is really only good for longer mileage intervals. On a motorhome it wouldn't be that much of an advantage as we usually time out before mileage comes into play.

Re: At 80,000 miles switch to Synthetic?

Reply #3 – January 10, 2017, 11:42:28 am

Thank you.
Just went out & checked. WHITE JUG!!
Stay with that or go full synthetic?

Re: At 80,000 miles switch to Synthetic?

Reply #4 – January 10, 2017, 11:45:09 am

Unless we go south for the winter we don't even get 5,000 miles on the engine per season.
Oil change--with (2) two quart oil filters and 12 qts of Rotello 15W-40 each fall usually less than $60.

Re: At 80,000 miles switch to Synthetic?

Reply #5 – January 10, 2017, 11:52:53 am

If I went by mileage I would go over 3 years, not good. Change every other year. Delo 400 same as my cranes.

Re: At 80,000 miles switch to Synthetic?

Reply #6 – January 10, 2017, 11:55:44 am

Used Rotella in my class A truck sold the truck at a million miles. Brother used Rotella in his class A truck solt at over a million miles. What I use in our coach no real reason to switch.

Roland

Re: At 80,000 miles switch to Synthetic?

Reply #7 – January 10, 2017, 12:46:57 pm

Why the 80,000 mls ? is this some kind of milestone that I am unaware of ? the reason I ask is that I met a guy in Oregon last fall and some CAT guy had told him and sold him on a bottom end job at 80k for his 88/89 3208. didn't have the heart to tell him he'd been .......well you know

Re: At 80,000 miles switch to Synthetic?

Reply #8 – January 10, 2017, 12:51:25 pm

Quote from: Olde English – January 10, 2017, 12:46:57 pm

Why the 80,000 mls ? is this some kind of milestone that I am unaware of ? the reason I ask is that I met a guy in Oregon last fall and some CAT guy had told him and sold him on a bottom end job at 80k for his 88/89 3208. didn't have the heart to tell him he'd been .......well you know

It used to be the rule to roll new rod and main bearings in the 3208 at 100,000 mi.

Re: At 80,000 miles switch to Synthetic?

Reply #9 – January 10, 2017, 01:00:58 pm

Quote from: Roland Begin – January 10, 2017, 11:55:44 am

Used Rotella in my class A truck sold the truck at a million miles. Brother used Rotella in his class A truck solt at over a million miles. What I use in our coach no real reason to switch.

Yup, I did the same with all my trucks and coaches, only I used Delo, both great oils, will never switch brands, in a rut, I guess.

Re: At 80,000 miles switch to Synthetic?

Reply #10 – January 10, 2017, 01:08:31 pm

Quote from: craneman – January 10, 2017, 12:51:25 pm

It used to be the rule to roll new rod and main bearings in the 3208 at 100,000 mi.

Thanks for the info' Craneman or at least I think so. When we get back from Rockie Point in the spring I'll get under the coach pulling the bottom end. Oh boy it's been a long time since the last time, so while I still can then I will. Can't give it to anyone then natter myself as to the quality of the job.!!

Re: At 80,000 miles switch to Synthetic?

Reply #11 – January 10, 2017, 01:25:41 pm

Quote from: Olde English – January 10, 2017, 01:08:31 pm

Thanks for the info' Craneman or at least I think so. When we get back from Rockie Point in the spring I'll get under the coach pulling the bottom end. Oh boy it's been a long time since the last time, so while I still can then I will. Can't give it to anyone then natter myself as to the quality of the job.!!

The trucks were simple to work on nothing in the way of dropping the pan. The 100,000 mile was just for the first 100,000 miles after that 175,000 This information is from the mid 80's from truck mechanics at that time. Filters are better now and so is oil. But it was a cheap insurance back then.

Re: At 80,000 miles switch to Synthetic?

Reply #12 – January 10, 2017, 01:45:59 pm

The old saying is if it aint broke, dont fix it. The oil you are using has been around and is widely accepted as great oil. Engines logged lots of miles before sythetic. I would leave it alone. What will you gain?

Re: At 80,000 miles switch to Synthetic?

Reply #13 – January 10, 2017, 01:52:49 pm

We use "Transynd" in the Allison, because Brett liked it. But I'd not go with synthetic in a engine, especially one with a "few miles".

Re: At 80,000 miles switch to Synthetic?

Reply #14 – January 10, 2017, 02:03:10 pm

I run mobil delvac 1 5w-40ESP synthetic in my engine. 25,000 mile change intervals per the cat book I found in the binder (2500 gallons of fuel x 10mpg)

The extra protection of a synthetic and the better cold flow of the 5w vs 15w is worth it to me. Pep boys runs 30% off online orders and delvac 1 rewards online usually bring the price down to conventional or even cheaper, making it a no brainer.

Re: At 80,000 miles switch to Synthetic?

Reply #15 – January 10, 2017, 02:22:39 pm

What's nice for me, is I've always been able to use the same oil for the engine and gen.

Re: At 80,000 miles switch to Synthetic?

Reply #16 – January 10, 2017, 02:32:01 pm

Whatever diesel oil you use in the engine will work for the generator, diesel or pos propane!

Re: At 80,000 miles switch to Synthetic?

Reply #17 – January 10, 2017, 02:40:32 pm

Quote from: RvTrvlr – January 10, 2017, 02:32:01 pm

Whatever diesel oil you use in the engine will work for the generator, diesel or pos propane!

Might explain what "pos propane" means. What I meant, was, if changing to synth, I'd change the gen at the same time, jus' sayin'

Re: At 80,000 miles switch to Synthetic?

Reply #18 – January 10, 2017, 02:45:15 pm

I use rotella T6 full synthetic. I go by hours + when I get around to changing oil. The filter I use has a built in bypass filter (extended drain) At least 15,000 miles. It's not too much more than dino rotella at walfart.

Somwhere on the interwebs people claim dino provides better corrosion protection than synthetic while sitting for long periods.

Re: At 80,000 miles switch to Synthetic?

Reply #19 – January 10, 2017, 03:11:38 pm

Quote from: RvTrvlr – January 10, 2017, 02:03:10 pm

I run mobil delvac 1 5w-40ESP synthetic in my engine. 25,000 mile change intervals per the cat book I found in the binder (2500 gallons of fuel x 10mpg)

The extra protection of a synthetic and the better cold flow of the 5w vs 15w is worth it to me. Pep boys runs 30% off online orders and delvac 1 rewards online usually bring the price down to conventional or even cheaper, making it a no brainer.

What do you run in your coach.

Re: At 80,000 miles switch to Synthetic?

Reply #20 – January 10, 2017, 04:06:09 pm

Quote from: krush – January 10, 2017, 02:45:15 pm

I use rotella T6 full synthetic. I go by hours + when I get around to changing oil. The filter I use has a built in bypass filter (extended drain) At least 15,000 miles. It's not too much more than dino rotella at walfart.
Somwhere on the interwebs people claim dino provides better corrosion protection than synthetic while sitting for long periods.

Krush bring up a good point. Lots of people on either side of the issue. All race cars use synthetic oil now but how about long term storage for RV engines?

Another interesting article:

Quote "There are many differences between synthetic oils. The differences can be in quality and the protection they provide. Not all synthetics are purely synthetic. The battle between Castrol and Mobil is on this issue. Some partial synthetics are marketed to unknowing consumers as being 100% synthetic. Castrol is a good example. There are no polyalphaolefin synthetic molecules in the Castrol Syntec. However, they are allowed to market it as synthetic due to some legal issues regarding the definition of 'synthetic.' They changed the definition to include the highly refining process of a petroleum-based oil, called hyrdocracking. This became a fight between Castrol, Mobile and the National Advertising council as Castrol tried to get them to loosen the definition to their liking." end quote.

Might apply to the foods we eat. Organic or organic?

Pierce

Re: At 80,000 miles switch to Synthetic?

Reply #21 – January 10, 2017, 04:29:35 pm

That is one reason I use only Amsoil as it is the first and true synthetic oil that our coach loves. Engine, Tranny, rear end all same make.
JohnH

Re: At 80,000 miles switch to Synthetic?

Reply #22 – January 10, 2017, 04:49:55 pm

Will get some flack but have been using Amsoil for over 35 years in everything and swear by it in our coach,put it in with 208K
miles and it took about 4k miles for the oil to turn dark,next time you change oil make a note how long it takes the oil to turn
black.The 2 majors replies as why not to use synthetics are the manufactuers do not recommend it and "I am happy with what
I use",my answer would be ,the manufactuers are in business to sell engines not to make them last longer . What about when
tubeless tires came out,or detergent oil,or none wooden spoke wheels,serpentine belts.Have rebuilt hundreds of turbo's and
99.9999 of them failed because of oil coking up the passages,that is virtually eliminated with synthetic.Just read the cummins 8.3
book about the cleaning of the air compressor passages because of varnish,with synthetic that it also eliminated.

Re: At 80,000 miles switch to Synthetic?

Reply #23 – January 10, 2017, 05:25:13 pm

I replaced petro 2 cycle oil in my Kawasaki 500 with Amsoil. Before, it smoked and I had to wait a couple of miles after city driving to race the Honda 750s/Nortons or I had a lot of missing from fouling the plugs (and lost). After Amsoil, no smoke and all the Hondas/Nortons were history. I still use it in my chain saws. I still have an old Suzuki PE250 that has gone Barstow to Vegas twice at a 120/1 mix. The head has never been off. After I changed the ports and went to a forged dykes ring piston in my Kawasaki, I had a Corvette with huge slicks come up from Los Angeles to race me. I showed him how I could start it with one hand on the kick start. The race was a non-event. I let him start first but had pulled in front by the time I shifted to second. Amsoil rules for two cycle bikes.

On the other hand, the 300SD gets it's oil changed with petro 15-50 every 3K and with almost 450K it has very faded paint but running like new. It's semi-retired now but always ready to go.

Pierce

Re: At 80,000 miles switch to Synthetic?

Reply #24 – January 10, 2017, 06:02:33 pm

The only thing I would worry about changing to synthetic is your engine may start leaking oil

Affiliate Notice