The Truth to Motor Oil

Warpig Racing · Post by **Warpig Racing** » Tue Aug 15, 2006 6:36 pm

Yesterday, a friend told me that the new motor oils have a rating of SM, which does not have zinc in it and maybe missing phosphorus as well. He told me that motor oil with a rating of SL has these ingredients in it. So the only oil that is rated SL is diesel motor oil and truck oils. He said that the gov't has mandated that the zinc be removed from all auto oils which is the explanation of posts about cam failures due to lack of zinc in the oil.

Can anyone else confirm this?

What is the difference b/w gas and diesel oil, if any?

plowboy34 · Post by **plowboy34** » Tue Aug 15, 2006 7:06 pm

I have been informed of this same thing. From what I understand it only affects flat tappet cams, not roller cams. I do not know this part for absolute fact but that is what I understand. There are still oils with zinc in them, you just have to make sure the oil your getting has it.

stranger · Post by **stranger** » Tue Aug 15, 2006 8:52 pm

gm has a flat tappet additive.with the zinc.

87ranger · Post by **87ranger** » Wed Aug 16, 2006 5:11 am

yes that is what i understand also, zinc is not very good to breath in, and when the oil goes past your rings and gets combusted the converters only catch the hydrocarbons, not the mineral therefor it is released into our atmosphere for inhalation. the oil fomulation change has been coming for years, this is one of the reasons why i push roller cams over the older flat cams so much.

MercuRanger · Post by **MercuRanger** » Wed Aug 16, 2006 4:47 pm

Hot Rod had an article on this within the last 6 months.

Warpig Racing · Post by **Warpig Racing** » Wed Aug 16, 2006 10:53 pm

So is it true about the difference b/w SM and SL ratings?

Is there a difference b/w diesel and gas oil?

MercuRanger · Post by **MercuRanger** » Thu Aug 17, 2006 3:47 am

According to Hot Rod and the cam companies, yes. They recommended using the Diesel oil for break-in on a new engine.

cgrey8 · Post by **cgrey8** » Thu Aug 17, 2006 5:23 am

Does running synthetic buy you anything here?

87ranger · Post by **87ranger** » Thu Aug 17, 2006 11:53 am

suddenly a flat tappet cam isnt worth the hassle is it?

MercuRanger · Post by **MercuRanger** » Thu Aug 17, 2006 2:33 pm

cgrey8 wrote:Does running synthetic buy you anything here?

For break-in, no (from what I've been told). Synthetic is too slippery and doesn't let the rings seat properly.

After break-in, who knows?

MalcolmV8 · Post by **MalcolmV8** » Thu Aug 17, 2006 5:25 pm

MercuRanger wrote: For break-in, no (from what I've been told). Synthetic is too slippery and doesn't let the rings seat properly.

I often wonder about that myself. What about vehicles that come from the factory with full syn though?

87ranger · Post by **87ranger** » Fri Aug 18, 2006 5:14 am

that stuff about breakin on mineral oil befor switching to synthetic is crap, synthetic oil manufactures even recomend breakin on theyere stuff now, my 2005 e150 work van comes from the factory with 5-20, there is no way that ford would issue that oil in those wehicles if they thought they would have all of these warrenty issues. the only reason youd want to breakin on mineral oil is because your only going to dump right away to get ride of the assembley lubes and other products used during the build. and if your going to dump it mineral oil is cheaper to dump.

cgrey8 · Post by **cgrey8** » Fri Aug 18, 2006 6:17 am

I'd heard more companies were starting to recommend 5w-20 over 5w-30 or 10w-30. However none of the typical places here in the south carry such a thin mix. The closest thing I've seen without special ordering is 0w-30 synthetic.

I suspect the move to 5w-20 is for fuel economy, not for better lubrication properties.

cjcnomor4 · Post by **cjcnomor4** » Fri Aug 18, 2006 7:57 am

fords 5w20 is semi synthetic for the most part. its what we use everyday. there is a full synth 5w20 available but its more money and not used in a 21.95 lof

cgrey8 · Post by **cgrey8** » Fri Aug 18, 2006 8:36 am

Cjc,
Are there any official Ford docs that address any benefits to using fully synthetics or synthetic blend oils? Any plans for Ford or other car companies to begin requiring the use of synthetics to maintain warranty?