opinions on synthetic oil

Where synthetic oils excell is when we experience temperature extremes... either raging cold or unsufferably hot. For anything else, synthetics are much of a bargain.

For the oil itself... are you selecting a PAO base stock oil or are you opting for "hydro treated" conventional oil base stock. PAO base stocks are more stable than hydroisomerized base stocks... They are better at resisting viscosity change at temperature extremes and they (as far as I am led to believe) resist shear in conventional use (but I am also led to believe that shear can be a concern when the oils are used in a hydraulic type situation as found in diesel engines with HEUI injection systems).

Oil change interval... 8000Kms is 5000 miles... and yes, since about MY 08 or 09 (memory thing) standard duty maintenance schedule is 6 months or 5000 miles. Pretty good in it's own right....

While conventional oil may begin to exhibit viscosity change due to molecular shear as it approaches the end of it's service life, one of the biggest concerns remains to be add-pack depletion... The add-pack is the "secret sauce" that is added to oils to combat acid formation, foaming, detergents, additives to keep impurities in suspension so that they vcan be carried to the oil filter for removal... Lord knows I'm only touching on the big stuff and forgetting so much (I'm not a petrochemist, I don't play one on TV and I didn't stay at a Holiday Inn Express last night).

While many synthetic oil purveyors are suggesting extended oil change intervals, Ford of Canada is insisting on copies of maintenance records for most mechanical failures. If your records show a chronic lack of maintenance... don't shoot me - I'm only the messenger. If you get someone to "cook" some receipts for you.... then you wont be welcome in my house... dishonest is dishonest. (Recently we had a customer insist his 09 diesel truck wasn't modified.... the tech still had trouble gettig our factory scan tool to communicate with the truck - and then we noticed the piggyback connector for the diesel particulate filter delete... how can we deal with someone that lies to us?). Modern engines are a bear to repair or replace...

Back to the oil..... Synthetic motor oils may offer "some" improvement in fuel mileage.... I do not know if producing PAO base stocks creates another problem in place of any petrochemical considerations - could it be that producing PAOs uses the equivalent (or more) of conventional oils/fuels to produce it? Hydroisomerized base stocks depend on conventional oil for their production so there isn't a whole bunch of "save the planet" to be had there.

I've been involved in the automotive trades for over 40 years.... I had my brief fling with synthetics... today? All of my vehicles get conventional motor oils - all of them are changed at the recommended interval... From what I have seen..... I will not discourage anyone from using synthetic lubricants - I WILL discourage people from trying to run extended change intervals - I don't think that Joe Average will ever see the benefits of synthetic MOTOR OILS repay the monies paid for their use.

My 2009 F150 has a regualr service oil change interval of 7500 miles. I've been doing something shorter (around 5k miles).

Ed

Depends where you are and how long it takes to put on 6000 miles. Personally I wouldn't push it much past 6000 or 6 months, and use a quality Wix , Putolator, or equivalent filter (Napa Gold, Motorcraft, or Mopar are all pretty good)

Pretty much what Jim said. About the same length of time in the automotive trades - I'm running Synth (Mannheim) in my PT Cruiser and regular oil in my Mystique

The only engines that benefit from using synthetic oils are stationary engines that run at a constant RPM. The only automobile engine that I can think of that would benefit from using synthetic oils are the generator only types used in true electrics, like the Volt that run at a constant RPM. Semi synthetic oils are a better choice for the average conventionally powered vehicle engines IMO.

Would you would recommend ignoring the requirements of auto manufacturers that specify syntheic oil? Why do you suppose some manufacturers require syntehetic oil for some engines (for example GM requires synthetic oil for Corvettes and some Cadillacs)?

Ed

If one changes oil every 5,000 to 7,500 miles or six months WOF, yes.

"Mike Hunter" wrote in news:4b5dd300$0$20629$ snipped-for-privacy@news-radius.ptd.net:

Gee I guess I don`t need to care that my eng starts at 20 below 0F then. Yes Syn help with cold starting. KB

I have to disagree with you. Conventional engines benefits from using synthetics if the owner is going to keep the car a long time. Synthetics lubricate better, particularly at low temperatures.

Jeff

I was speaking in general terms. In Antarctica at 150 below, they use kerosene in the crankcase ;)

Perhaps but you are speaking of a minor percentage of new car buyers, however. Nearly 90% are traded on another new vehicle in three to seven years on average.

Antartica doesn't get to 130 below, let alone 150 below.

YA right

The record low temperature on the planet is -129 F.

So, of course, I am right.

Jeff

Vostok Russia coldest recorded temperature -91 degrees C, -132 degrees Fahrenheit

like to see your dino oil there ;)

Naw, i'm joking, i'm only on my first two synth oil changes. (by two meaning i put it in two vehicles for the first time and haven't changed it yet)

Not confirmed.

That's what I said, you are correct but I meant to type 130. ;)

Synthetics have ONE advantage. That advantage isthey resist extremes of temperature - maintaining their viscosity much better than regular oils. That is IT.

This means they are an advantage on engines that experience extremes of temperature - either in environment or operation. So cold starting in Athabasca or Winipeg or Nome, or hot operation in death valley, or Pheonix, or any other hot place, or any engine worked hard with high operating temperatures - particularly if built to fine tollerances, all will benefit from using synthetic oils.