Switching Back?

[Tim Keeler]

Lately I've been reading alot about the unnecessary use of synthetic oil in my '73 L-82. I have noticed more gaskets 'weeping' oil in the three plus years I've been using synthetic. I'm thinking of replacing my normal fill with a high grade conventional oil. Anyone have any thoughts or see any problems w/ this plan? Thanks, Tim #26883

[Joe L.]

Re: Switching Back?

Tim----


In my opinion, "switching back" will cause no problem, whatsoever. However, I don't think that it will cure your oil seepage problems because I don't think that those problems have anything at all to do with your use of synthetic oil.

[Jeff]

Re: Switching Back?

Joe,


You may recall from past posts that I am a fan of SHCs but I must admit that if there is one possible drawback it might be less of a tendency to bloat or swell gaskets than naturally occuring hydrocarbons (or possibly a difference in the additive packages if the base oil is not at fault). I have noticed this phenomenon, myself, but retorqueing the offending surfaces at their new gasket thickness usually solves the problem.


JP

[Duke W.]

Re: Switching Back?

Synthetic oil is probably a waste of money if you drive no more than 3000 miles between changes. Look at Pat Bedard's column in the January '00 Car and Driver.He interviews an oil industry expert on what type of oil we should use in our old "keeper cars". Turns out the best off the shelf products are HD diesel blends meeting API spec CF-4. Over the years the critical anti-corrosion, anti-wear, and dispersant additives have been reduced in spark ignition blends (currently API spec SH) because their combustion byproducts aren't kind to catalytic converters. The diesel blends have much higher concentrations of these critical additives.


Duke

[Ray Gitt]

Re: Switching Back?

Tim, back in the seventy's when I worked for a Chevrolet dealership, we were having a problem with new pickups loosing oil. We had a lot of customers who were very unhappy with GM products. At that time, the push was on to sale multi viscosity oils. We had GM engineers trying to solve the problem. No real answer was at hand. A gentleman from the GM training facility in Tigard Oregon by the name of Pard Wilson (who I took my mechanical training under) recommended that we go back to straight weight oil. 20/20, we did, gave away few oil changes to those unhappy customers and the problem went away. I made it a practice to stay with 20/20 wt oil in all my GM vehicles. I have had no oil leak problems for many years, through a 1967, 1968, 1969 and my present 1976 which was the first vette I bought new. Taking a few extra minutes of your time, When I went to work for a County here in Oregon. They had always used straight weight oil (20, 30, 40, 50)with no problems. Two years ago a new Superintendent insisted that we start using multi weight oil. The older vehicles started having oil leaks, and the new vehicles with silicone gaskets are doing fine. One of the reasons they wanted this change was to improve fuel mileage (by the way, this was the same song and dance GM, Ford, Chrysler etc used to help meet EPA ratings). The records on these vehicles show a very small improvement in mileage, but the cost of oil leaks out weigh the savings they try to sale us on. Sorry to take so much of your time. But, I thought you would like to know. Did you know that is also there reason for going to that thing they call a spare tire and wheel). By the way, 20 wt is getting hard to get here on the West Coast, I don't know what I'll do if it takes a hike like all the other good products that no longer exists. Save the Wave and Drive to Stay Alive. Ray

[Ray Gitt]

Re: Switching Back?

Tim, back in the seventy's when I worked for a Chevrolet dealership, we were having a problem with new pickups loosing oil. We had a lot of customers who were very unhappy with GM products. At that time, the push was on to sale multi viscosity oils. We had GM engineers trying to solve the problem. No real answer was at hand. A gentleman from the GM training facility in Tigard Oregon by the name of Pard Wilson (who I took my mechanical training under) recommended that we go back to straight weight oil. 20/20, we did, gave away few oil changes to those unhappy customers and the problem went away. I made it a practice to stay with 20/20 wt oil in all my GM vehicles. I have had no oil leak problems for many years, through a 1967, 1968, 1969 and my present 1976 which was the first vette I bought new. Taking a few extra minutes of your time, When I went to work for a County here in Oregon. They had always used straight weight oil (20, 30, 40, 50)with no problems. Two years ago a new Superintendent insisted that we start using multi weight oil. The older vehicles started having oil leaks, and the new vehicles with silicone gaskets are doing fine. One of the reasons they wanted this change was to improve fuel mileage (by the way, this was the same song and dance GM, Ford, Chrysler etc used to help meet EPA ratings). The records on these vehicles show a very small improvement in mileage, but the cost of oil leaks out weigh the savings they try to sale us on. Sorry to take so much of your time. But, I thought you would like to know. Did you know that is also their reason for going to that thing they call a spare tire and wheel). By the way, 20 wt is getting hard to get here on the West Coast, I don't know what I'll do if it takes a hike like all the other good products that no longer exists. Save the Wave and Drive to Stay Alive. Ray

[R.Dykstra]

Re: Switching Back?

Hi Tim Good question concerning the synthetic oils of today.As a lubricant sales rep for one of the more respected majors, and also a multi Corvette owner, I must also agree with the post of not really a benificial choice for your application. Reason is according to my sources is that the manufactures make up of gasket material pryor to 1982 in & around is not synthetic compatible,thus the tendancy to leak.If the engine has been refurbished recently then of course it should have compatible seals.My believes are if you change the oil at regular intervals with a oil of recommended spec and quality(ie;76 Nascar)cheap plug,that you will enjoy a long life from your motor.Any how thats just my take on this subject.