RIP non synthetic motor oil

[DavidGraves]

Does anyone here understand the consequence of shifting from non synthetic to fully synthetic motor oil for my "old" 2005 Ram 5.7 Hemi ?

We just completed a round trip to the east coast and I was dismayed to find I could not buy non synthetic anymore along most of the route.

Fearing the switch to synthetic during a long trip I just kept the level up in our older Dodge Ram with oil I had brought along.
The new to me Dodge is a 5.7 Hemi with about 130 K miles.

Need some guidance and many thanks

David Graves

 

[Foy]

I've read lots of anecdotes describing problems, mostly leaking seals and gaskets, after a switch from dinosaur oil to synthetic in older trucks, but I've never read what would appear to be an analysis with a good statistical sample. Maybe they're out there, just never found one.

I bought my 2002 F350 7.3 diesel in 2004 with 96,500 miles in 2004. I ran it with dino oil until a 2012 winter trip to Utah's ski country. Switched from dino Rotella 15W-40 to synthetic Rotella 10W-40 for the lighter weight in the extreme cold anticipated and experienced. Never switched back. No leaks or other problems experienced.

Foy

 

[Vic Harder]

go ahead and switch.
Synthetic to Conventional Switch Myth | Bob Is The Oil Guy

 

[ntsqd]

I think when the phrase "older engines" and related is used the authors are talking more like 1980's and older. A 2005 does not come even close to qualifying as an "old engine" as far as I'm concerned. Maybe because the newest truck that I own is 1996. My oldest is currently a 1973, although it is about to receive an '04 power-train. Which is going to mess with my oil regimen as currently everything runs on Delo 400 15-40.

 

[michelle_east_county]

"Old" engines or cars are anything from before when you were born [emoji16]. But seriously, I've anecdotally observed it seems like problems when switching to synthetic oil come up with major changes in base weight; say, going form 10w-30 to 0w-30 synthetic because the latter really is more stable at higher temps but supposedly without the need for as many viscosity index enhancers or modifiers even if both have a rating of "30". But, the thinner base stock ("0" rather than "10") might make for more leaks or oil pump cavitation if oil with a "0" wasn't originally specified by engine manufacturer for anything above cold ambient temps. Our auto repair shop recommended continuing with 10w-30 for both our '03 Jeep Rubicon I-6 and a '97 Ram van-based Roadtrek with the 5.2 Magnum V-8 whether it was synthetic, or not. We used synthetics there with no problems. And, even Ford had previously recommended 5w-20 synthetic or blend on a '87 and '97 Mercury Sable with the 3.0 Vulcan V-6 that originally called for 5w-30 non-synthetic.

So, check with manufacturer or a mechanic who keeps up on this.

Remember, the oil is all hydrocarbon-based. Synthetics may be derived from heavily synthesized natural gas or crude oil; non-synthetic is derived as distillate from crude oil. The former may be better simply because it's refined and reconstructed exactly as the manufacturer wants it.

 

[Casa Escarlata Robles Too]

Michelle good info.
Thanks
Frank

 

[craig333]

Its getting tough to find straight 30 for my Jeep

 

[michelle_east_county]

Craig333, what year is your Jeep? There might not be "safety in numbers." Most engines over the last 45 years have been designed to run on thinner base stock multi-grade oils for the incrementally better Corporate Average Fuel Economy (CAFE) of first a 10w-40 and later a 10w-30 over straight 30, 20w-40 (try finding that!) or 20w-50. Later, 10w-30 was replaced by 5w-30, 5w-20, 0w-20, etc. Yes, in a few cases (Honda, for one) the US recommended oils were lighter than for same engine sold elsewhere, but many such as Ford "Triton" V-10 were specifically designed around (oil pump pickup design, rings I think) thinner oils and specifically did not recommend thicker. The GM 8.1 V-8, last made in about '07, did allow for the old standard of straight 30 if ambient temperatures were always above 40 degrees.

 

[craig333]

My Jeep is a 1960 and the engine was designed in the forties.

 

[michelle_east_county]

Yep, heavier oil it is! But, I'd bet if you researched it you'd find some of the heavier multi-grades might be OK. Here's something else I didn't realize until a few years ago re older engines: For emission control purposes of small amounts of oil getting past rings and burning during combustion, some additives that used to be included in motor oils to prevent excess wear with non-roller cams were taken out now that everything new has a roller cam. There are additives you can buy that claim to replace them but I know nothing of whether they work or cause other problems.

 

[DavidGraves]

Howdy Michelle

Does that mean I can switch from 5 W 20 in my 2005 5.4 Dodge Ram to a synthetic ?

What weight would you suggest ?.....light load driving in 30-100 degree Farenheit.

Thanks

DG

 

[Mighty Dodge Ram]

I’m not a petroleum engineer, just my anecdotal experience. I used to be brand loyal rather than “type” loyal, I ran Pennzoil conventional in my Dodge 5.9 gasser right up to 302k miles when it was sold. Chevy calls for either conventional or synthetic in my current (2002) 6.0 gasser, 5w-30. The engine has an iron block and aluminum heads and has a reputation for “piston slap”, especially when cold. I switched to full synthetic and experienced increased slap and a feeling of additional vibration when accelerating…again, anecdotal. I now use semi-syn, same weight, for high mileage engines and am happy with it. I do carry additional oil with me but haven’t had a problem finding it while on the road. Just a thought, YMMV.

 

[michelle_east_county]

DavidGraves, ' dunno. Check manufacturer technical service bulletins or good mechanics.