Motor oils; synthetic vs. regular

RR Conductor · 12-07-2010, 12:51 PM

I know I said I'd posted my last but got a question to through out.

For you diesel engine owners, especially Cummins (in Dodge); have any of you switched to synthetic oil and if so did you notice an increase in mileage or other engine characteristics, like having to lower idle RPM? I've talked to a few people, including a couple of mechanics, and they seem to favor staying with regular oil verses synthetic. So, what say any of you that have switched to synthetic or are staying with regular, i.e. Rotella T 15W-40 and why.

Thanks for any response with this question.

A VERY MERRY CHRISTMAS to all

**FPM III** · 12-07-2010, 06:59 PM

I've owned two diesel pickups (Ford and GMC) since 1996 and have always used Rotella-T (and I change my own oil). For the type of driving I do, I see no justification to move to a synthetic oil. While there may be some long-term benefit, how many people actually keep their vehicles long enough to collect on that benefit; plus get a payback from all the additional money invested in these higher-priced synthetic oils. The engine is engineered to run on the oil as specified in their owners' manual- What more do you need?

Personally, I think the argument for using synthetic oil vs. non-synthetic is similar to the argument as to whether you should put premium gasoline in a vehicle that's engineered to run on regular.

Seann45 · 12-07-2010, 07:37 PM

I have been using Rotella synthetic since the day I got my truck... I want the best protection I can get for it... the syn has allowed me to extend my oil change intervals..(with oil analysis) I have switched over to synthetic fluids for everything... will never go back. Synthetic keeps the engine much cleaner.. and does a much better job of protecting the turbo if you shut off without letting it cool down..

RR Conductor · 12-08-2010, 03:43 PM

Thanks guys for the reply posts. What you both say is absolutely true and I don’t think there is a right or wrong answer, depends on what works best for your type driving. My two sons are both die hard synthetic oil users but so far I’ve stayed with Rotella T 15W-40 and have had good luck. I’m getting 21 running light and about 12.5 to 13.8 mpg towing, depending on terrain, etc. I’m hoping for better mileage in time as the engine only has 16K on it so it's hardly broke in being a diesel.

Again many thanks for the replies and here’s wishing the two of you and everyone on the list A Merry Christmas and a Healthy, Happy New Year.

P.S. Glad I'm retired, with this cold weather we've been having back east workin' on the railroad can get right down cold!

av8arkie · 12-08-2010, 05:01 PM

I use Rotella as well. I have been told (by an aircraft mechanic) that full synthetic oil does not scavenge dirt as well as regular, or semi synthetic oils do. Mobil used to make a synthetic aircraft oil and engine failures went up (bad thing) in engines running that oil. My truck is dealer maintained and GM seems to feel Rotella is just fine so I will stick with it.

kipper · 12-08-2010, 06:30 PM

When you start you engine in cold weather , petroleum based oil is very very think and takes more time to reach the correct viscosity , and thats not good , less lubricating protection . Synthetic oil may be as thick but reaches the correct viscosity quicker and in hot operating temps synthetic oil does not break down , but the hotter petroleum oil gets the more it breaks down and that means less engine protection . I use only synthetic in my cars and truck , and I am an ASE master mechanic .

Seann45 · 12-09-2010, 08:37 AM

Starting your vehicle at -40 you can hear the difference that synthetic oil makes... esp if you have more miles on it... I had a little Mazda 6 with over 300,000 miles on it... was going to trade it in .. first start at -40 with dino in it and I KNEW how good synthetic was.

av8arkie · 12-09-2010, 08:40 AM

I will NEVER have to start my truck at -40. I will NEVER be in -40! Just sayin!

**FPM III** · 12-09-2010, 11:30 AM

If you have a block heater on your vehicle (or a heated garage), who cares how cold it gets? The oil will be warm enough that it would not be much different than starting the engine in July.

When enough glow plugs died on my 96 PowerStroke that it wouldn't start in the cold, I just started plugging it in. I had it on a timer so the block heater only ran for about three hours before I left for work. It always fired right up. As a bonus, you started getting warm air from the heater too. This is a good thing because diesels generally take longer to warm up than gassers.

kipper · 12-09-2010, 03:55 PM

Sure , in a heated garage , but a block heater only heats the coolant , when the engine has not run and has sat over might the oil is down in the pan , away from the engine block its as thick as honey .

kcconawa · 12-09-2010, 10:35 PM

I have a 2000 powerstroke w/253,000 miles and have always used regular oil. I get around 11.4 MPG towing 31 ft Designer. Engine still has zero leaks in the garage, absolutely no oil on the floor. Mechanic has never put a wrench on engine for any issue.

I have put a pencil to it and cannot, in my mind, justify the extra cost.

Albertaguy · 12-10-2010, 09:05 AM

Quote:

Originally Posted by Seann45

I have been using Rotella synthetic since the day I got my truck... I want the best protection I can get for it... the syn has allowed me to extend my oil change intervals..(with oil analysis) I have switched over to synthetic fluids for everything... will never go back. Synthetic keeps the engine much cleaner.. and does a much better job of protecting the turbo if you shut off without letting it cool down..

Seann, I feel for you buddy, if I drove a Chev I would want to get all the help that I could!!!!

JUST KIDDING. I am due for my first oil change on my new Ram the first week of January and I have several years of free oil changes that were part of the negotiation when I bought my truck. In my old truck I used Amsoil but have no idea if it made a difference as it only had 65,000 Kms on it when it went back.

My truck is garaged so I think I will stick with regular oil for a while. I only have 3600 Kms on it in 6 months so I don't put that much on the clock and I have only pulled my 5th wheel on one trip so far.

RR Conductor · 12-10-2010, 01:37 PM

Albertaguy, unless you can ask for a particular band name oil at your dealership it's my understanding that the Mopar diesel oil is very close to Rotella T 15W40. I've been getting the free oil changes with my '08 Dodge since I bought it and have let them use Mopar oil except for two changes when the dealership just happen to have Rotella T in stock. I realize all this is useless information but hey, thought I'd tell ya anyway.

Albertaguy · 12-10-2010, 11:15 PM

Quote:

Originally Posted by RR Conductor

Albertaguy, unless you can ask for a particular band name oil at your dealership it's my understanding that the Mopar diesel oil is very close to Rotella T 15W40. I've been getting the free oil changes with my '08 Dodge since I bought it and have let them use Mopar oil except for two changes when the dealership just happen to have Rotella T in stock. I realize all this is useless information but hey, thought I'd tell ya anyway.

Any info helps and I will ask my dealer when I go there.

I'm not sure if I asked you this before, but what place in VA are you in. I lived in Colonial Heights in the 50's when my father was on course at Ft. Lee. It sure was an eye opener for a young Cdn kid and I ended up with quite a Virginia drawl when I returned to Canada.

RR Conductor · 12-12-2010, 05:37 PM

Quote:

Originally Posted by Albertaguy

Any info helps and I will ask my dealer when I go there.

I'm not sure if I asked you this before, but what place in VA are you in. I lived in Colonial Heights in the 50's when my father was on course at Ft. Lee. It sure was an eye opener for a young Cdn kid and I ended up with quite a Virginia drawl when I returned to Canada.

RE Mopar diesel oil being close to Rotella T; I was told this by the mechanic that set my truck up at the dealership where I bought it in Wilmington, NC (saved almost $10K buying the truck in North Carolina and I can buy a lot of diesel fuel for ten grand!). I've let them put Mopar diesel oil in, as I mentioned in an earlier post, for all but two changes and so far I've had no problems.... "knock on wood."

As to where we live; we're in the southeast corner of the state close to Virginia Beach.

Seann45 · 12-13-2010, 10:45 AM

Quote:

Originally Posted by Albertaguy

Seann, I feel for you buddy, if I drove a Chev I would want to get all the help that I could!!!!

JUST KIDDING. I am due for my first oil change on my new Ram the first week of January and I have several years of free oil changes that were part of the negotiation when I bought my truck. I.

My truck is garaged so I think I will stick with regular oil for a while. I only have 3600 Kms on it in 6 months so I don't put that much on the clock and I have only pulled my 5th wheel on one trip so far.

Condolences on having to drive a Ram.... good engine in it.. too bad the rest is pure.... LOL
Kidding aside guys the DYNO says... you get more power to the wheels with synthetic... and of course you all know if you dont use the power you get better mileage...

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