i have read more than once--don't use diesel oil in autos. that being said, synthetics may not apply. if you know enlighten me please.

frog.

 

When the life of my engine is on the line I would rather spend an extra 10 bucks and stick with Mobil1 !

 

Car and Driver had a piece on oils several years ago. IIRC, the diesel oils are better at lubricating, but are not kind to the catalytic converters that gasoline engines employ.
I use diesel oils (Velo and Rotella) in my old truck (no cats), but stay with gasoline type oils in the rest of my fleet.

Larry
code5coupe

 

You can go to Big Lot's and get the four-quart convenience sized jugs of Mobil 1 for $11.99

 

My last oil change I switched to the Wal Mart synthetic.For my 85 this oil is probaly 10 times better than what was available 20 years ago when the C4s were hitting the streets.

 

why in the world are you guys letting wally world change your oil. heck get the oil and get your kids to help. helps strenghting family communications and values, and then when your 16 year old son or daughter take the car for a spin then they will know how to check the oil when they fill it up when they bring it home. my 5 year old son know a heck of a lot about cars the most 16 yr olds ..... be safe thats my $.02 worth rosco

 

Anybody got any info on the Rotella Synth. oil? From what I've read in other threads, diesel dino oil can be good for a gas engine, but I can't find any info about diesel synth. oils in searches on the forum.

 

The regualr blend castrol GTX. I like it and its always available at my local autopart store. I have seen the synthetic castrol but for a higher price. Like i said i switched back to the regular blend becouse i did not feel any diffrence nor was the car idling smoother. I did not notice any diffrence from synthetic compared to regular blend. I have heard that synthetics add a couple extra ponys and smooth out the idle /temp better.

Its alway good to hear everyone elses take on certain things becouse
you can put them togther and come up with a diffrent maybe even better one in the end. Or learn things you will never even dream about(example diesel oil in gaspowered auto) thats new to me.

 

http://www.rotella.com/products/

Google is your friend.

Larry
code5coupe

 

I used to buy the WalMart synthetic but its not available at my store anymore- hasnt been in months.

 

On bobistheoilguy.com, there are quit a few satements about how Rotella, & other HD diesel oils are better than other oils ( including synthetics) at protecting against thermal breakdown. Also according to a lot of posters on that board, there really is no proof that the diesel oils with their higher levels of sulpher & I think they said paraffin, poisoned the cats. I`m just reporting what I read -- these folks know a lot more about oil than I ever will, or want to

 

I'm certainly no expert but have learned a few things when I was in Tech school for diesel mechanics. Diesel oils are better against thermal
breakdown, they have to be, a diesel engine ignites the fuel by heat
of compression not spark plugs, so there is tremendous heat. A diesel
tractor trailer gets used hard and needs that protection. I would not
run a paraffin based oil in my car especially if you take it out for short
runs and don't get it heated up good. Paraffin is wax, and wax is liquid
when its hot but solid when it's not. That why you can get crud build up
in your engine. I'd stick with a good synthetic imo.

 

You raise a good point...but what do we do to protect our engines since the anti-wear additives are very low? A quote from a message by Duke: "I just don't like the new SH oil because most if not all of the ZDDP anti-wear additive has been removed." What's a Vette owner to do?

 

I've never seen the Wally World synth. Just Castrol, M1 and Quaker State offerings locally.

 

High levels of ZDDP in and of themselves aren't necessarily indicative of good performance as can be seen from the results of this recent AMSOIL commissioned stufy of motor cycle oils: AMSOIL Motorcycle Oil “White Paper” (1 MB pdf file)

For those that can't download that, here is a quote from the wear test:
"The ASTM D-4172 4-Ball Wear Test is a good measure of the existence and robustness of an oil's additive
chemistry. It is used to determine an oil’s ability to minimize wear in case of metal-to-metal contact. The test
consists of a steel ball that sits atop three identical ***** that have been placed in a triangular pattern and restrained
from moving. All four ***** are immersed in the test oil, which is heated and maintained at a constant
temperature. The upper ball is then rotated and forced onto the lower three ***** with a load measured in
kilogram-force (kgf). After a one-hour period of constant load, speed and temperature, the lower three ***** are
inspected at the point of contact. Any wear will appear as a single scar on each of the lower *****. The diameter
of the scar is measured on each of the lower ***** and the results are reported as the average of the three scars,
expressed in millimeters. The lower the average scar diameter, the better the wear protection of the oil. In this
case, the load, speed and temperature used for the test were 40 kg, 1800 RPMs and 150° C respectively.

Interestingly, the SAE 40 oils with the highest and lowest levels of zinc, Maxima Maxum 4 at 2,464 ppm and
Pennzoil Motorcycle at 1,010 ppm, had identical results. Royal Purple, with an average level of zinc (1,474 ppm)
had the largest wear scar (nearly 55% larger than the next closest wear scar size). Zinc levels for those oils performing the best, AMSOIL MCF, Mobil 1 MX4T, Motul 300V Sport and Torco T-4SR ranged from 1,061 to 1,762 ppm.
The SAE 50 group showed a similar trend. Golden Spectro 4, with the highest zinc level (2,162 ppm), performed
less than average in the 4-Ball Wear Test, while the Motul 300 V Competition, with the lowest zinc level (1,048
ppm), tied with AMSOIL MCV and Torco T 4SR with the best test results.
The results strongly suggest that simply having high levels of zinc is not sufficient to effectively minimize wear."