need synthetic oil???

[Goherdsw]

Hey all...does my 96 need synthetic oil, during changes?

It has 40,000 miles on it....

I was wondering if Jiffy Lube was trying to "upsale" me.

Thanks

Scott

[BullShifter]

yes you should use synthetic. take a look at the oil cap. Mobil 1

[TEXAS-HOTROD]

I agree with B.S.
I use Amsoil synthetic in everything, including my lawn mower.
I use Mobile 1 in my Corvette because that's what was in it when it left Kentucky.

[supramk3]

Do you guys reccomend switching over to synthetic on an 85 L98 with 65k miles?

[mqqn]

Originally Posted by supramk3

Do you guys reccomend switching over to synthetic on an 85 L98 with 65k miles?

Hi supramk3 -

Synthetic oil is better oil.

I ran dino oil for 135k miles in my 1989 Formula 350 Firebird with no problems, the car did not use over 1/2 quart of oil in 3500 miles (the change interval I used with that car.

If you go synthetic you can extend your change intervals to help recoup the $ difference.

best regards -

mqqn

[RahX]

well the only thing you have to watch out for is that synthetics will find a leak that regular oil couldnt think of finding. people say it creates leaks but thats bs, it can squeeze out of smaller spaces than regular oil and thats why some engines will leak oil when you go to synthetic. keep that in mind if you have any similar problems when you switch over. its not a big deal as any good synthetic is compatible with regular oil so switching to and from synthetic shouldnt give you any problems.

[spinktec]

The reason for the Synthetic oil on the LT1 engines is cooling (notice all 92 and newer vettes have an oil temp guage). The reason for Mobil 1 is that it was the only synthetic widely available at the time of the engine's debut in 1992. The idea came from the development of the LT-5 in the ZR1 a few years earlier. Mobil 1 is not the only oil that will work in the LT1 or LT5 either; but to know for sure look on the back to be certain it list that it meets standard GM4718M. I'm pretty sure Castrol Syntec has it listed, and I think I've seen it on a couple others.

[racook2]

Yes, use synthetic oil...

[bunyz06rabbitt]

For me, Royal Purple feels slipperier than Mobil 1 and meets GM4718. I use it in my '01 Ford Focus Wagon, '02 Vette Z06 and '03 Ram Hemi QC. I extend the change interval to 6000 miles and no problems whatsoever!

[sub006]

I use Castrol synthetic in my newer vehicles. When I changed my '90 Suburban over, I increased the drains from 4,000 to 7,000 miles with K&N oil filters.

My wife's '98 BMW would ask for an oil change at about 10,000-mile intervals. Her '04's computer turns on the yellow "oil service " light at 15,000!

I've always wondered about the new 'Vettes coming from the factory with Mobil 1 installed. Whenever I install a rebuilt or factory crate engine, the instructions always caution you to break it in for at least 3,000 miles on conventional oil before switching to synthetic. So do the new 'Vette engines have special machining, ring materials, cylinder coating, or what???

[mqqn]

Originally Posted by sub006

...snip

I've always wondered about the new 'Vettes coming from the factory with Mobil 1 installed. Whenever I install a rebuilt or factory crate engine, the instructions always caution you to break it in for at least 3,000 miles on conventional oil before switching to synthetic. So do the new 'Vette engines have special machining, ring materials, cylinder coating, or what???

Hi sub006 -

While break-in is still considered by many to be some crucial affair that requires an almost cult-like procedure to endure the engine will run properly over it's expected liftetime...it is largely unnecessary today.

In the old days, engines were delivered to the consumer with machining spooge and other contaminates in the engine, machined surfaces were much less precision, and the metallergy was primitive when compared to today.

I have heard the break-in stories - the machined surfaces of the piston rings and the cylinders and what not must be "polished in" prior to any prolonged heavy-duty use.

In the face of that information, I find it interesting that each new Corvette is put on a chassis dyno at the factory before it ever leaves the building, and is driven up to 75 mph and all the components are given a thorough check, transmission, brakes etc.

Synthetic oil is simply better oil, with qualities that allow it to last longer than conventional oils. I am not going to go into the factors (search google for "hydrocarbon chain" and "shear"), but suffice it to say, having better oil in your engine will in no way hinder the ability of components in the engine to seat together and perform.

The only compelling reason I have ever heard for not using a synthetic oil was touched on earlier in this thread by RahX. While synthetic oil will not leak out of engines because the "molecules are smaller" , the better deteregents in high-end synthetics can have more of a cleaning effect and could remove sludge from a dirty engine in such a way as to expose a leak where one had been plugged by sludge before.

Using synthetic should be a no brainer for people - its better for your engine, it better for the environment (longer change intervals) and in the long run will save you money.

We are lucky today to have engines that will run ~250k miles routinely. Better metallergy, closer tolerances on mass-produced engines, and last but not least, synthetic oils, have allowed us to take this kind of endurance and reliability for granted.

30 years ago, it was unusual to have an engine last much more than 100k miles.

BTW - the last crate engine I installed (GM Goodwrench 350 long block for chevy truck) did not specify dino oil - it did specify a special GM break-in lube to be added to the original oil fill to validate the warranty. It amounted to 6 ounces of additional lube (and I'll bet it was synthetic.....)

best regards-

mqqn

[TEXAS-HOTROD]

I switched my C4 to Mobile-1 because the oil needed changing, I wanted to convert to a synthetic, and Mobile-1 is all I could get in short notice from the local Wal Mart. I had been using Castrol w/good results, but knew that a synthetic would be better. Eventually it will be changed over to Amsoil.

My Silverado, my wife's Tahoe, the bike, the Biscayne and the lawn tractor all get Amsoil synthetic. I have a few customer's vehicles that also use Amsoil.
I have one customer that doesn't keep track of his mileage and his services are always over extended. Amsoil recogmends change intervals at 25K miles w/an oil filter change mid term. His Z-71 had oil changes more like every 30K/35K miles, usually w/o a filter change in between. I would change out the old synthetic, fill it w/Castrol oil and a cheap filter and let it run while I greased/checked everything. I would then drain the cheap stuff and fill it back up w/Amsoil and install the Amsoil filter. Flushing the system between servicing makes a big difference and keeps the oil cleaner.
The truck developed the famed leaking intake manifold gasket at around 100K miles, so I was able to inspect the inside of the engine. Even though the oil changes came out really dirty/nasty looking, the inside of the lifter valley and the bottoms of the valve covers were amazingly clean. This was proof that synthetic is better.
I always hear people say that they change oil every 3K miles (then they proceed to say that they use Pennzoil). 3K miles? Yeah, right. Now that's a waste of oil. They usually have the engines that are plugged full of goop.

Since the development of the C-4, Corvette has been on a weight-savings diet. One item that was sent to the scrap pile a long time ago is the oil cooling system. W/the use of synthetic oil, it didn't matter if the oil temp got a little higher than normal. Higher oil temperature for a synthetic would only help evaporate any moisture that might be in the engine.

I also use synthetics in the trannies and in the diffs as well.