My 67 400 has 24,000 original miles. I am a fan of synthetic lubricants and have used them in the past. However, I haven't talked myself into going with synthetic motor oil in my Firebird. Has anyone out there made the switch? Is it the way to go?

Vince
'67 400 convertible

This is a good question. I am sure that a few will chime in. I would ask yourself a few questions. How much do I drive my car? Is my engine sealed well?(leak oil) Can I afford the extra cost? How often do I change my oil? I personally like the extra protection that synthetics provide. The oil does not break down as easy as conventional oils do. You may see a slight mileage increase and should gain engine life also. Synthetic oils will leak from an engine that did not leak with conventional oil though! Good luck with your decision.....

</font><blockquote><font size="1" face="Verdana, Helvetica, sans-serif">quote:</font><hr /><font size="2" face="Verdana, Helvetica, sans-serif">Synthetic oils will leak from an engine that did not leak with conventional oil though! </font><hr /></blockquote><font size="2" face="Verdana, Helvetica, sans-serif">Are you talking from experience or just spreading rumors? I have used synthetic oil since 1976 and it has never caused any leak.

Synthetic lubricants do have an inherent detergency that cleans and removes conventional motor oil deposits left over in an engine. However, motor oils are designed to help swell seals slightly to prevent leakage. The only time you would observe seal leakage is if the seals are already damaged or showing signs of leakage around them. As long as the vehicle has been well maintained, and in good mechanical condition, it can be switched to a synthetic lubricant at any mileage.

I actually had a leak occur in my 350 Chevy 10 years back. Maybe it was coincidence? It started leaking from the rear main after I broke it in with conventional oil. Maybe I should have stated it differently, sorry. Your motor MAY leak more with synthetic oil, where it did not with conventional oil. I am currently running synthetic in 2 of my cars.......

I have used synthetic oil in my cars since 1980. Synthetic oils will not cause oil leaks or an engine to burn more oil, on the contrary, an engine that tends to burn oil will burn less with synthetic due to the molecular structure of synthetics (all the molecules are uniform in size, petroleum based oils do not have a uniform structure). The above comment is correct regarding oil leaks - if the engine's sealing/gasket system is sound, then synthetic oils will not cause them to leak. However; if there is already wear or deterioration and leaks that have sealed themselves over time due to dirt buildup, then synthetics will naturally clean away the dirt, thereby exposing the leak, but not causing the leak.

As far as putting synthetic oil in a brand new engine (before break in) there is conflicting information. Some say that due to todays better machining tolerances, that putting synthetic oil in right away will not prevent rings from seating properly. Others say that synthetics are too slick to use in a brand new engine and the rings will not seat. If you are worried about this, then run a petroleum based oil for 500 or so miles and then switch to synthetics.

The advantages are well worth the extra cost - less friction which means lower oil temps and better gas mileage. Synthetics clean better and do not break down under high heat conditions like petroleum oils and synthetics have a much lower pour point (well below 0 F).

I hope this helps.

Tom

Thanks for all the replies. If there are members out there that trust synthetic oil in their old Birds then I guess that I should too. I had no problem switching to it in my'93 Firehawk. For some strange reason, switching to it in my old girl was a hard decision. I guess it's time to make the switch.

Vince

fyi

The Corvette's have been facotry filled with synthetic oil for several years. They even come with a oil cap the says, Special Lubricant Required and the Mobil 1 Logo. GM part number for that cap is12555685, go buy one if you doubt me, its around $7. Also it been said by Scott Settlemire, Camaro Production Team that all F-Bodys were alos filled with synthetic oil starting in Sept of 2001. They also installled it in prior years. So the breakin therory does not seem to make any sense. I personally install synthetic oil in everything I own as soon as possible.

btw-I use Amsoil synthetic's. They are made in the USE (Superior, Wisconsin) and not a product of the bigh oil companies.

I couldn't agree with WS6 more! I've used Amziol since I was 9 years old in my first Vehicls. A 1973 Harley Davidson Shortster, and in my Snowmobile. (my parents are distributors)

Synythetics have come a long way. Amzoil is the oldest, and has done more R&D than any of the "new" synthetic guys, and are always on top with any cross compairisons. see link:
http://www.hoigto.com/motoroil.htm

I have a 73 GMC stepside with a small 307. When I bought it, they told me they were concerend on how long the engine and tranny would last. I switched to Amzoil in both, (power, gas milage, and drivability all went up) and they both lasted over 20 more years of service! Until my nephew ran it dry on tranny fluid and oil... tranny died, but the motor still runs! Not great but runs!)

I too have amzoil in our two light weight Harleys, the 97 Blazer, the 73 GMC, the 67 Firebird, the 66 Mustang, the 61 Bug etc...

It works for me! - Brett - 67 Drop Top 455!

Wow Brett. Thats alot of engines you have to keep up!

Yes Brett , thats a lot of Amzoil!
No wonder your parents have to be Distributors!

Bjorn

Hi... my name is Brett... and... ah... I'm a... well... a.. car-a-holic!

(group says all together... "HI Brett")

What can I say, If I could... I'd have a lot more
(and will in the future)

Thanks - Brett - 67 Drop Top 455!

And the group says: " HI BRETT"!
:p Bjorn

Hey Guys,

Nice to see the positive comments on synthetic oil. The correct spelling is "AMSOIL". I have been a distributer since 1980 or '81.

And yes, the Corvette has been using Mobil 1 for several years now.

Tom

Tom , I thought it was spelled Amsoil ( when I used it in my dirt bikes it was 10-15 yrs ago...so you kind forget)
Just thought Brett knew what he was talking about! lol
but....Brett?

haha , Bjorn

When I was at the p.o.c.i. convention a couple of years either jim wangers or john sawruck said that penn.10w30 turbo oil was the best to put in pontiacs along with a 50/50 mixture of prestone/distilled water for cooling.

FYI

It used to be spelled AMZOIL.

But the big yellow oil company sued them for using the zoil claiming they had it trademark. The name AMZOIL was derived from the founders neame A.J. Amatuzio

It was rumored the reason the suit was brough was the they were trying to buy out the Amzoil company and he would not sell. So in order to keep from loosing everything fighting a big oil company who had more lawyers than Amzoil had dealers, they agreed to change the name to Amsoil and get on with business.