At 150k on My 85 LG4, Is it okay To switch To Sythetic when I do My next Change?

Is there any POint ?

And whats a Good Synthetic?

So many questions, Not enough Answers...


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85 Z28 - Daily Driver
60 Ranchero - Project ( Money Hole )

 

From my knowledge, the main reason for using synthetic is to reduce overall wear. With 150k on your engine, its useless now, those bearings have received a great amount of wear. Now don't get me wrong, synthetic is the best, and it never hurts to always use the best you can. I just think for the money involved, you wont get recipreciated in value. As far as brands, I perfer Mobil 1 and Castrol Syntec. Don't forget to use a good filter too, like Mobil 1 or AC Delco Gold.

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Rob
'86 TA 305 TPI

 

One thing you may notice by switching to syntheitc that late is an excess of oil consumption. When I made the switch on my engine I was going thru a quart every 2 weeks. I went back to conventional and didn't have near as severe consumption.

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1985 ASCD Ram Air Trans Am
http://www.execpc.com/~karpsta/home.html
to find out more
-=ICON Motorsports=-

 

I switched mine at 123k with no knowledge of its history. I started by running the AMSOIL crankcase flush with 4 qts of petroleum oil and a new filter, which I ran for 30 minutes, then drained and changed the filter with the fresh synthetic. Consumption was high at first, but changing the rock-hard valve seals on the intakes to umbrella type took care of that.

There is a point to it, even with high mileage: It will reduce further wear; cold starting will be easier (if you're in a below-freezing climate); gas mileage can improve (benefit reduced if consumption is high).

Petroleum-based oils leave sludge and varnish wherever they go. Synthetics are good detergents, and will desolve these deposits. This will dirty the synthetic quickly, which is why AMSOIL recommends running the flush before putting in the synthetic.

With the exception of Mobil, the synthetics the "majors" produce serve primarily to enable them to say they have a synthetic product. Mobil 1 is probably the most readily available, but AMSOIL is the only company willing to compare their products to other synthetics - a big indication of confidence and quality, in my opinion.

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82 Berlinetta, orig V-6 car, now w/86 LG4/TH700R. 2.73 unlimited slip. Cat-back from '91 GTA, Accel HEI SuperCoil. AMSOIL syn lubes bumper-to-bumper. Daily driver, work-in-progress (LB9 w/ZZ3 cam, TBD heads, exhaust, paint, etc.).
57 Bel Air, my 1st car. 0.030 over 396, Weiand Action+, Edelbrock 1901 Q-Jet, Jacobs Omnipack, 1-3/4" headers, TH400 w/TCI Sat Night Special conv & shift kit, 3.08 10-bolt, AMSOIL syn lubes bumper-to-bumper. Best 15.1 @ 5800' Bandimere. Daily driver while Camaro was being put together.

 

i switched my gravely to 15-50 mobil after 30 years and it's oil use is lower and i believe the oil stays cleaner. i know an air cooled engine isn't the same as a water cooled SBC, but it's something to consider. if it were my engine i'd mix sythetic and regular oil.

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-=ICON MOTORSPORTS=-
1st & 3rd

 

Rather than using half synthetic/half petroleum (with who knows what in each), use a synthetic blend or semi-synthetic. That way you would be getting a package that is purposefully blended, rather than possible dueling additives. I know everyone says the products are compatible, but the best bet is always to stick with the same product in the crankcase at any given time.

 

I have an 88 305 TBI Firebird with ALMOST 190,000 miles on it and still running great. I switched to synthetic quite a few months ago. I use Mobil 1 with the AC delco oil filter. I replace both at approx. every 3000 miles.

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Shouldn't bother putting this but hey what the heck:
1988 Maui Blue Firebird 305 TBI stock (WITH NEW PAINT!! YAY! )