Flyer

I'm getting ready to change oil & filter. I plan to use Rotella 15w-40 and I noticed I have a gallon of Rotella synthetic 5w-40 I had for my old F-150. I had a thought of a blend of the two. The synthetic meets CH-4/SL specs. Any thoughts on this?
Thanks

Lil Dog

1. Don't blend synthetic oils with conventional or semi/syn oils.
2. Gasoline engine oils have different additives that are not approved for Diesel service.
3. Blending different grades of oil are not recommended. The different properties of the oil will not just mathmatically change the oil viscosity.


My $0.02, use the synthetic 5W-40 in the wifes car and use the Diesel oil in the CTD.

Charlie Hardin

If the synthetic meets ch-4 specs, doesn't that mean it works for diesel? I would agree not to mix standard and synthetic, although I think the directions say it"s OK.

Hemi Cat

why do you want to start out an oil change with a mix of oils? I think some synthetic oils say it will mix with petrolium oils, and that is ok to add a quart or so during a service interval to get you home. I would never recommend to start out with a blend of synthetic and petrolium oils. Watch your api classifications.

kd460

Hey Flyer, go over to this website and ask that question. While I'm not saying yes or no, check it out. These guys eat drink and sleep oil. Some even mix oil types like you want to do. At least you will be able to get more info so you can make the decision a little easier. Good luck, Kevin

http://theoildrop.server101.com/ubb/...ubb=forum;f=22

TxDiesel007

Its kinda like mixing batteries when you mix diesel oils,

Usually works for a while, YET the risk is that results can be tragic, i wouldnt do it, its not worth the risk of your investment.. I use 15W-40, and since i havent had this truck but 3000 miles, i look forward to using fleetguard filters, and 15W-40 Rotella Diesel Oil.... every 5000 miles....

TxDiesel007

Flyer

I will check out the oil forum. I agree there might be a problem with mixing these types. Is a blend of syn and petrol mixed or blended at the refinery? When I get a convincing answer I will post. For now the buggy will get a petrol change this time. I also got a K&N oil filter. any thoughts on this choice. There are plenty of Fram and Purolator types in my neck of the woods but I will have to hunt down a Wix or Cummins. One last thought, my drives are mostly highway with a bit of local and off-road. My manual says 5000 mi, dodgeram.org says 6000 mi and of course the oil companies want 3000 mi. between changes. I would like to hear any thoughts.

Thanks to all, this site and the posters are a great info source.

Dr. Evil

There's also some really good oil info here:

www.bobistheoilguy.com

Lil Dog

There is an oil change place in our town that has open cans of the K&N, Fram, NAPA and Hastings.
Needless to say I would NOT use K&N or Fram. If the diesel filters are anything like the automotive ones they have on display its pretty poor construction.

The Hastings and NAPA filters looked pretty stout. The Fleetgaurd are the better filter, I would pay for the MOPAR filter before the Fram or K&N IMHO.

The poor construction filters can pass small particles of the filter media into the oil. This usually gets collected in the smaller oil ports like the upper valve train or in the Piston Cooling Jets. If you search on piston cooling jets you will see how short a life the engine has without piston cooling. Cracked pistons, siezes components just to give the highlites.

With replacement engines well over the $10K mark, why chance it with a $3 savings on a filter??

infidel

You guys are trippin, there is absolutely nothing wrong with mixing petro oil with synthetic but I don't see any advantage in it. If you mix the two your change interval should be that of the petro oil.

Flyer

OK The posters on the OilGuy site said no problem. I already did the petro change with the K&N filter. I will watch the dipstick to see how clean it stays. My next change (in 5000 mi.) will be to the synthetic with a Cummins or Mopar filter.

MasseyMan1089

I agree. If you cannot spare a few dollars and buy a good oil or one kind of oil for your truck, maybe you shouldn't have that much of a truck? Just my .02 worth

Lil Dog

True, but the additive packages of different oils can cause adverse effects with respect to the detergents and acidity/soot inhibitors.

If I mixed them, I would do an oil analysis on regular intervals to be sure the additive packages are not degrading at an abnormal rate.

My $0.02

Dufrain

Then there is the semi synthetic

ride_a_hd

Out of curiosity, has anyone tried the "Amsoil dual remote Oil Filtration System"? This fella sure seems to swear by his (half-way down page)! Seems like a win-win setup...
Dave

http://www.off-road.com/dodge/deserttank/index4.html