Synthetics are definitely better lubricants. I believe the concern is not whether you should use one or the other but that once you start using one, you must not switch! If you are starting with a brand new motor I would definitely use a high quality synthetic. If you are working with an older motor that you do not know the history of back to day one (and most of us don't) I would stick with the old petro. If I remember correctly, engines that have traditionaly run with petroleum oils develop a looser fit than an engine run on synthetics and when you try to switch to a synthetic this can become an issue.

Like I said, it's been a long time since I read up on it so if anyone else can elaborate please do.

I guess another good question would be...."is a synthetic oil a synthetic oil or are there differences in the brands? " . My '93 calls for Mobile 1. Would the engine really care if I were to put in something like Royal Purple or some other synthetic?
If I ever get my 454 back and put together, I plan on running some type of synthetic, but do not have a clue as to which would be the best.

Glenn, good point. I did go check out Red Line's web page and it's just like Mobil 1's--we are the greatest is the bottom line. Like most of the WWW, it's one giant advertisement. Rick may have some useful info since he's researched but when I research something through the mfr, all I ever get is their hype. That's why I came here. I want honest testimonials from people who have used a lot of it for a long time. Does it really reduce wear more than conventionals? Does it keep the engine clean(er)? Is 12,000-18,000 between oil changes practical? Is it worth $9.25 per quart(Red line's cost around here)?

Valvoline was always my brand. I worked for Valvoline/Ashland Oil back in '89-'92. They sent Mobil back to the drawing board on synthetic oil. They couldn't figure out how to make their oil compatible with petroleum base oil back then. Valvoline has a full synthetic (petro-base compatible) and a semi synthetic (50/50) mix, which were pretty good products.

BTW/FYI-Napa store brand 5w-30,10w30,etc. are made by Valvoline.

I'm going to try out Amsoil in my Tahoe in a couple weeks. During my stay in Saudi Arabia, I was talking with a couple of fellow aircraft mechanics about Amsoil. And they said that they had great results with this oil. Their gas mileage went up 1-2mpg and the oil change interval was 25,000 miles (filter change is every 7,500 miles.) And could be prolonged if you send in a oil sample to the company ($20.fee) and everything checked out OK. Also the engine temp. was 15-20 degrees cooler running. The oil analysis will also tell if you are having the start of a component failure. Way cool. So I will write back on this thread in a few weeks and tell if the gas mileage increases and engine temp goes down.

Sarge

I've always used Mobil1 in my cars & trucks. Privategod>> that was a great article you found. To re-emphasize, Synthetics are better at removing dirt & sludge so if you have alot of sludge to begin with, when you remove it, you may have leaks. Keep in mind that it was the sludge that was sealing off the leak & NOT the gasket(s). As far as semi-synthetics,,, Mobil Drive-Clean-Blend is approx 8% synthetic so I doubt you'll get any major leaks from that. The other semi-blends are less than 6-7% synthetic, not really worth the extra cost IMO. Synthetic oils have the same sized molecules, that what blocks sludge from happening in the first place. Also, they are much smaller allowing them to reach more "hidden" parts of the engine that they are lubricating. Synthetics flow easier during "cold" startups & have a MUCH higher boiling point. You guys (& gals) can run whatever you like, I'll stick with my Mobil1. just my $.02

I use Havoline 5W30 and PF35 filter. They have done me well in the past and why screw with perfection.......

I had a new bowtie crate motor installed last September. My engine guy insisted that I run 5/30 (regular petro) for the break-in. He said that in his experience using synthetic to break a motor in results in the rings not seating properly. He also said that given the infrequency of hard driving, mine's a daily driver (no long hauls) 10 miles R/T to work, regular oil would be just fine. The only hard driving she sees are the occasional light-to-light education/"you shouldn't rev your Mustang's engine unless you want a good view of my tail-lights" sessions.

As far as filters, he recommended only using ACDelco filters as they contain an additional seal to prevent "back-flow?".

Anyway, that has been my experience and the advice I've been given.

Good luck,

Andrew

ben i use castrol gtx 20-50 and 1 QT. lucas oil stabilizer in the 76 corvette 335hp. the 78 ,355hp. and my ford one ton with a 460 got 330000 on the 460

Guess I better try to find the receipt for the synthetic I bought and return it for the regular 'dino' stuff. Glad I saw this thread before putting "The Toy" up on the ramps.

Thanks everyone!


Jim O.
Save the Wave...!!!

Wow, alot of different experiences and opinions here!
Personally, I break all my engines in with dino oil, then switch to synthetic (Castrol Syntec)

VW Deisel Jetta 355,000 kms, still going strong
Chev Silverado 415,000 kms ... ditto
97 Ski doo (oil injected) 18,000 kms ... ditto

I switched the vette over 2 years ago at about 65,000 miles and noticed no leaks, or oil loss and it actually ran cooler. My 2 cents...

Just bought a new daily driver and after the break in I'll dump the dino and pour in the syntec.