interesting article oil from GM

[Mike M.]

Re: interesting article oil from GM

i was under the impression the 90 up LT5s were filled with Mobil 1. will check my 90 owners manual later. i've been using Mobile 1 in my 90 ZR1 since i bought it used in early 91. mike

[Patrick H.]

Re: interesting article oil from GM

Several years ago (since it's a 2000 model) I switched my Pontiac Montana's oil to Mobil1 at its first oil change. It started leaking from the oil pan gasket the very next week, and took the useless technicians at the dealership months to figure out (even though I told them it was the pan gasket). Call it an old wive's tale if you want, but the synthetic sure seemed to have an ability to "cause" a leak in my case.

I've been using non-synthetic oil in all of my vehicles ever since then. I suspect the new 2008 will stay with Mobil1 since that's what it came with, but that will be the only one.

Patrick

[Joe L.]

Re: interesting article oil from GM

mike-----

If the synthetic oil was specified, it will say "...oil that meets GM specification 4718-M". However, I don't think that this oil was specified for LT5 engines until 1993 or 1994. Of course, one could use that oil, but I don't think it was specified or used in PRODUCTION until then.

[Patrick H.]

Re: interesting article oil from GM

Joe,

I know this is getting down to small details, but the Callaway Twin Turbo came "factory filled" with Mobil1 in 1987.

Patrick

[David H.]

Re: interesting article oil from GM

Be sure and read the new flat tappet break-in process very carefully before useing synthetic. the instructions have big warnings as does the crane cam web site about breaking in their cam with the zinc oils and only switching to syn. after 3000 miles.

Also is a warning about little used (hobby) cars with flat tappet cams to stay with zinc oils because the oil runs off of the parts during storage. From my bad experience; 2 brand new mild hp cams in the trash after only 100 miles or less! useing regular mineral spirit oil. I followed the directions and the only change I made the last time was the oil. David

[Paul L.]

Re: Ken & Paul

Thanks Terry. The Owner's Manual is pretty vague on this topic. It does say to use SAE 5W-30 meeting GM Standard GM6094M. Now I ask: Would the average person know what that standard is? It does go on to say that for areas of extreme cold (-20*F, -29*C) that an SAE 5W-30 synthetic oil or an SAE 0W-30 oil can be used. That implies synthetic is OK. It's 0*F this morning so those temps are coming. Just to be cautious, I'll probably give the car about 5,000 miles and then change to Mobil 1.

[Chuck S.]

Re: interesting article oil from GM

I seem to remember the oil fill cap on my 87 convertible also saying Mobil 1 was recommended. That would mean factory fill was Mobil 1 long before the 90s. I did a search to try and confirm this, but no luck at Mobil or the NCM...anyone want to check their 87? Anyway, the original owner had used Mobil 1 since it was new, and I continued the practice.

[Terry M.]

Re: Ken & Paul

Check the label of the oil you intend to use, or check their web site. One or the other should show that the oil meets or exceeds that spec as well as a host of other car manufacturers specifications.

[Randy G.]

Re: Ken & Paul

Mike Gruber, the Valvoline Racing Oil Rep at NHRA National Events, reported to me that when the World Of Outlaw sprint car racers began cycling in the reduced zinc and phosphate "SJ" rated oils in there alcohol injected aluminum small block Chevy's in 2005 they experienced rod bearing failures at an alarming rate. Whenever the injected alcohol engines hit 10,000 RPM they would spin rod bearings in spite of having good oil pressure.

The reason he came to me was I lost 5 engines in 4 races due to rod bearing failures in my Top Alcohol Funny Car after 14 years of racing blown alcohol with no oil related issues at all using the same brand oil. I was sponsored by Pennzoil on a free products deal and was using Pennzoil's 60 wt GT Racing oil. Pennzoil reduced the zinc and phosphates to make their Racing oil "SJ" legal so it could continue to be sold over the counter when the updated rating requirements came out. Not only did we have rod bearing failures we started burning up pushrod tips along with other issues related to lack of lubrication. My car has a 3,500 horsepower aftermarket hemi V8.

Mike confirmed to me the reason the oils were changed had to do with emmisions systems and catalytic converter issues with higher zinc and phosphate levels in over the counter oils. Since diesel engines didn't have catalytic converters the spec didn't apply to diesel oils.

The solution which I continue to use today is to purchase Valvoline's "off road" racing oil which is not sold in stores. I have to buy it by the 55 gallon drum directly from Valvoline's race support trailer and it's only sold to race teams.

I have never had an oil related failure since. It isn't a "myth." I have the piles of parts to prove it.

Randy

[Randy G.]

Re: Ken & Paul

PS to my above post.

Mike also told me that the issue was the fact that the former higher quantity of zinc additives in the oils would transfer heat better and faster out of the bearing surfaces than todays EPA approved oils. It may be true that the newer generation of oils lubricates as well under putt-putt conditions, but under high load or extended load situations that create a lot of heat (like the sprint cars hitting 10,000 RPM, higher spring pressures on flat tappet camshafts and my engines with extreme loads) todays over the counter oils will not protect the parts as well as the older generation oils.

Randy

[Clem Z.]

Re: interesting article oil from GM

i put 4000 mile on my 88 siverado before switching to Mobil 1 and with 150,000 miles on it the engine is quiter than my 2008 C-6

[Clem Z.]

Re: interesting article oil from GM

GM speced Mobil 1 for the ZR-1 engines because they were having camshaft bearing journal problems in cold weather start ups because the dino oil was not getting there fast enough. mobil 1 "sticks" for the lack of a better term to the engine parts better than dino oil. they also switched the regular corvettes so the could do away with the "oil cooler" between the oil filter and the block because mobil 1 will takr higher temps.

[Philip C.]

Iam one of those detergent oil myth guys

My idea of an old engine is it has no oil filter.My understanding of detergent oil was that it carried dirt and what ever to the oil filter. The non-detergent oil did not so an old engine without a filter used non-detergent oil. The dirt and what ever stayed in the bottom of the pan and then drained out with the oil when you change it. So your saying these engines and small engines like lawn mower, etc can use detergent oil. Phil 8063

[Philip C.]

Iam one of those detergent oil myth guys

My idea of an old engine is it has no oil filter.My understanding of detergent oil was that it carried dirt and what ever to the oil filter. The non-detergent oil did not so an old engine without a filter used non-detergent oil. The dirt and what ever stayed in the bottom of the pan and then drained out with the oil when you change it. So your saying these engines and small engines like lawn mower, etc can use detergent oil. Phil 8063

[Clem Z.]

Re: Iam one of those detergent oil myth guys

the only thing i do not run detergent oil in is my air compressor because the instruction manual said not to. i change oil,mobil 1, once a year in my corvette and since it only has 4K or 5K miles on the oil i put it into my old siverado for another 10K miles or so.why waste good oil