which motor oil?

[Doug]

Here at our shop we work on a lot of new motor cycles, we use mostly synthetic oils. I also work on some old equipment and some diseals. I use Shell Rotilla. My 30 U I use Rotilla 10 40. Here in North Carolina I drive it all year, No problems. You can get this suff any place and put it in just about any thing and it works. I have read sevral reports on oils and Rotilla always does well It's a good all around oil. I also put 700.000 miles on my KW with any problems.

[oldmopar]

I run whatever name brand 5-30 or 10-30 that is on sale.
I feel the important this is frequent oil and filter changes every 1500-2000 miles or at least twice a year. 

[57plymouth]

I was the first to jump on the synthetic oil bandwagon.  I converted the entire fleet over to Mobil 10w30.  I live in South Carolina, so my mild winters mean winter driving, but the hot summers often garage the car!  That blend is what most if not all hobbyists use around here.  I liked the protection of synthetic.  I have personally seen several motors that have survived running with low pressure or no pressure due to low oil level (several long stories, mostly on the dragstrip).  The synthetic war fine in all my cars, new and old, but the 57 did leak a little out of the front seal. 

Then came all the horror stories about cams being wiped out by new oil with low ZDDP or zinc levels. 

I got scared, so I switched.

Now all my flat tappet motors get Rotella 30 weight or 10w30 if I cannot find straight 30 weight.  My roller camshaft motors still get the Mobil synthetic. 

With one notable exception:  I have a $600 Pontiac Sunfire I use to run around town.  If it blows up tomorrow I don't really care.  It has over 130K miles.  I use Valvoline High Mileage oil with a can of Restore in it.  Why?  Two reasons, my neighbor works for Ashland Chemical, which makes Valvoline so I am helping his job stay stable.  Also, I figure if there was ever a car that was beat on and has lived a hard life it would be this Pontiac, so the High Mileage oil may be hype or it may be insurance. 

Long story short:  I use Rotella.  If I cannot find Rotella, I use Delo.

[Carla]

There's been a good bit of publicity, of late, regarding the removal of some zinc-based additive chemicals from the standard motor oils, which additives are desirable for minimising bearing wear, but allegedly cause some sort of problems with the catalytic exhaust widgetry on modern cars.

According to the information circulating on the internet these days, the best choice for preserving the engines on the older cars which don't have the catalyst thingamies is to get a diesel-rated oil, intended for use in the generality of diesel truck engines.

Now, truth is, my knowledge of oil chemistry is on the close order of nil........and I've no real idea of the truth......or otherwise.....of the stories of engine failures from use of the newly revised motor oils in older engines.

Considering, tho, that the cost of the best oil one can get is ever so cheap compared to the cost....and time.....involved in pulling an engine down to replace bearing shells, I just bought a couple of cases of 'Shell Rotella' oil in single-viscosity 40 weight, for our engines.

Why single-weight, you may ask?.......we're located in the S. F. bay area of California, where we don't experience the extremes of weather which are the reality of many other areas. We don't need to have an oil which is the equivalent of 10 weight at low temperatures to be able to start engines in really cold weather, which, far as I know, is about all the multi-viscosity oil really does for modern cars.

Again, I must plead my own ignorance of the fine points of oil chemistry, but according to some comments on various internet boards by people who were......or at least were claiming to be......actual oil chemistry people, the necessary additives which make an oil 'multi-viscosity'.....I think they said 'long-chain polymers' or some such, actually reduce the lubricating quality of the oil to some extent, a trade-off for the multi-viscosity characteristics needed for low-temperature starting with modern engines.

My own 'take' on all this is that I'll pay the price for the diesel-rated oil, and change oil in our engines at every 1000 or so miles,  depending on the use the vehicle gets.....this may seem a bit needlessly wasteful, on one level, but its worth it to me as 'relatively cheap insurance' for the engine bearings.

cheers

Carla

[Go Fleiter]

 Modern Engine oils may have additives thgat keep dirt in circulation, thus stringently needing a full stream oil filter. Also, a newly rebuilt , clean engine may need another oil less additives than a dirty engine.

Castrol has good choice of Oldtimer oils since shortly.

Millers Oils is a fine choice: Be sure to check their site        http://www.millersoils.net   These oils in part are even less expensive than modern ones, but You must carry a supply with You, as You don?t  get them at common Gas Stations or super markets.

This year we had several articles in oldie magazines saying that a lot of old engines and transmissions are killed by modern and unsuited oils.

Greetings to Florida! Go

[Bob]

Mike,
In my 1940 Plymouth P-10 Business coupe I use SAE 30 weight like the manual calls for.

[48 Beauty]

Can some one tell me which motor oil to use in my 48 plymouth. thanks. mike