VERY IMPORTANT - - Engine Oil Alert

[Stich496]

VERY IMPORTANT - - Engine Oil Alert from a Corvette oil expert..

This is just an FYI. It should not affect owners of vintage cars who are using the proper API service category oil.

API has replaced SM with SN, and this is done in conjunction with an ILSAC update from GF-4 to GF-5.

S-category oils, SL and above, are NOT SUITABLE for vintage engines with sliding surface valve trains due to reduced anti-wear additive. Don't use S-category oil even if it's ten-buck a quart super-duper synthetic that the marketer claims will make your engine last a million miles.

Continue to use C-category oils in vintage engines. I'm not aware that the current CJ-4 spec that dates to 2007 is due to be replaced anytime soon.

If you're interested in all the bloody technical details on SN, you can start here:

http://www.api.org/certifications/engineoil/new/index.cfm

[TheSilverBuick]

Everybody's an expert.

Oh and the link doesn't work.

[LORENSWIFE]

One thing about living near the mexican border...it is fairly easy to get real chemicals still...
~Gail

[Stich496]

link works..

[Russell]

so what should I put in my 1968 289 mustang with 35k original miles? Its due for a change...

[Barry Donovan]

so what should I put in my 1968 289 mustang with 35k original miles? Its due for a change...

this means it is only getting better..

do anything but crazy bragging synthetics.

I have an engine that needs to burn conventionally too.. you iron blocks can get away with alot more.

I ise a synthetic blend and regular.. same old story getting better than ever.No more full pan of full synthetic. do add some if I want.. just not the whole base filled with it.
going by factory recommendations did not foresee an improvement in oils back then. Some sincerely can not do synthentic. I need to create some carbons. that is a way that they don't look at properly.. probaly due to making it seem like a pig. Older oils simply allow for carbons necessary for your engine. synthetics are not good for most of us... the mix blend stuff is about as far as it goes.

this is good news. I trust these changes.

[64falconsix]

so what should I put in my 1968 289 mustang with 35k original miles? Its due for a change...

I have done a lot of online research on this subject and even studied oil analysis data. There is not enough ZDDP (anti wear and scuffing agents) in new off the shelf oils to protect engines with flat tappet cams.With the increase in flat tappet lobe failures the cam companies have responeded with lobe Nitriding as an option and a market for specialty oils for flat tappet engines. Brad Penn , Comp Cams , and Valvoline conventional Race oils will have the level of ZDDP needed but the Penn and Comp oils are expensive and are not stocked locally,( in my area) the race oils in this area are by the case special order only. The recommendation I got from a friend who races nostalgia and runs a speed shop is to use your favorite conventional oil plus a ZDDP break in additive, such as from crane cams or comp cams.He said the racers running flat tappet cams use it instead of paying for specialty oils. Just add at every oil change, he also recommends the combo for stock flat tappet engines.I have been using Lucas oil break in additive with Valvoline 10w30 conventional. Advance auto in my area carries the Lucas additive.

[htrdharley]

I have been running Shell Rotella 15-40 in my 68 390 Ford for around 20 years with no issues. It is also cheaper than most other oil.

[BigBlockMopar]

One thing about living near the mexican border...it is fairly easy to get real chemicals still...
~Gail

Define 'Chemicals' please