oil

[Andy Miller]

I have recently purchased a 1961 Corvette. I am not sure of the SAE requirements in 1999 terms nor the synthetic verse regular oil. I want the best protection but no company promotes oil for old engines.

[Joe L.]

Re: oil

Andy----

Even if you could find some motor oil manufactured to 1961 standards and/or specifications, I wouldn't recommend that you use it in your Corvette. Motor oils have come a VERY long way since 1961 and the improved oils are usually always applicable to earlier models. Without a doubt, they're a VAST improvement over the 1961 vintage oils.

The latest American Petroleum Institute(API) rating for motor oil for gasoline engines is service category "SJ" and that's what you want to buy. Most quality motor oils that you find on the shelf will be "SJ"-rated, although there still might be some "SH"-rated stock around. As far as oil viscosity rating goes, I'd use the viscosity recommended in the owner's manual. In 1961, usually straight 20 or 30 weight oils will be recommended, but there might be a multi-viscosity option mentioned. These single-viscosity oils are available in the current API service category. Multi-viscosity oils have improved DRAMATICALLY since the 60s and I prefer them for all applications. For non-synthetic oils, I prefer Shell.

As far as synthetic oils go, I am a BIG FAN. It took me years to come around, but after considerable study and research, I am ABSOLUTELY convinced that they are FAR superior to any conventional oil and they're all that I will use in either of my Corvettes or, even, in my daily driver car. There is one caveat, though. I do not recommend the CONVERSION, without complete rebuild, of a "used" engine operated for years on conventional oil to synthetic oil. In my '92 LT1, I've used synthetic from day-one(it was factory-fill and required anyway). In my 69, I will be using only synthetic when I get it back on the road after completing a TOTAL engine rebuild and other work(SOON, I HOPE). I have heard, but never confirmed, that switching to synthetic in a "used" engine can promote oil leaks, and that is my only reservation about its use in such circumstances. For synthetic oils, I prefer Mobil 1.

One more thing: the closest thing you can get to 1961 motor oil today is the non-detergent variety available in some auto parts stores. This is a low quality, obsolete oil that I DO NOT RECOMMEND for use in any engine except those specifically requiring it. Even then, I would be EXTREMELY reluctant to use it.

[Joe L.]

Re: oil

Andy----

Even if you could find some motor oil manufactured to 1961 standards and/or specifications, I wouldn't recommend that you use it in your Corvette. Motor oils have come a VERY long way since 1961 and the improved oils are usually always applicable to earlier models. Without a doubt, they're a VAST improvement over the 1961 vintage oils.

The latest American Petroleum Institute(API) rating for motor oil for gasoline engines is service category "SJ" and that's what you want to buy. Most quality motor oils that you find on the shelf will be "SJ"-rated, although there still might be some "SH"-rated stock around. As far as oil viscosity rating goes, I'd use the viscosity recommended in the owner's manual. In 1961, usually straight 20 or 30 weight oils will be recommended, but there might be a multi-viscosity option mentioned. These single-viscosity oils are available in the current API service category. Multi-viscosity oils have improved DRAMATICALLY since the 60s and I prefer them for all applications. For non-synthetic oils, I prefer Shell.

As far as synthetic oils go, I am a BIG FAN. It took me years to come around, but after considerable study and research, I am ABSOLUTELY convinced that they are FAR superior to any conventional oil and they're all that I will use in either of my Corvettes or, even, in my daily driver car. There is one caveat, though. I do not recommend the CONVERSION, without complete rebuild, of a "used" engine operated for years on conventional oil to synthetic oil. In my '92 LT1, I've used synthetic from day-one(it was factory-fill and required anyway). In my 69, I will be using only synthetic when I get it back on the road after completing a TOTAL engine rebuild and other work(SOON, I HOPE). I have heard, but never confirmed, that switching to synthetic in a "used" engine can promote oil leaks, and that is my only reservation about its use in such circumstances. For synthetic oils, I prefer Mobil 1.

One more thing: the closest thing you can get to 1961 motor oil today is the non-detergent variety available in some auto parts stores. This is a low quality, obsolete oil that I DO NOT RECOMMEND for use in any engine except those specifically requiring it. Even then, I would be EXTREMELY reluctant to use it.

[Bill Baird]

Re: oil

I've used Mobil 1 for a number of years now (ten in my Vette, a few less in my other cars), and I've never had a problem with it. I've put it in engines I just built (after breaking in with conventional oil), as well as in worn engines. I've got the following comments:

- I've never noticed any more (or less) oil leaking with synthetic oil than with conventional oil.

- When an engine has had Mobil 1 in it for nearly all of its life, it sure is clean inside when you tear it down - sludge just does not form.

- When the temperature drops down into the teens (or below), regular oil starts to resemble molasses. Mobil 1, while thickening up a tad, still flows nicely.

- Synthetic oil gets just as dirty as conventional oil, so it's important to keep your oil change interval the same as with conventional oil.

Bill Baird

[Bill Baird]

Re: oil

I've used Mobil 1 for a number of years now (ten in my Vette, a few less in my other cars), and I've never had a problem with it. I've put it in engines I just built (after breaking in with conventional oil), as well as in worn engines. I've got the following comments:

- I've never noticed any more (or less) oil leaking with synthetic oil than with conventional oil.

- When an engine has had Mobil 1 in it for nearly all of its life, it sure is clean inside when you tear it down - sludge just does not form.

- When the temperature drops down into the teens (or below), regular oil starts to resemble molasses. Mobil 1, while thickening up a tad, still flows nicely.

- Synthetic oil gets just as dirty as conventional oil, so it's important to keep your oil change interval the same as with conventional oil.

Bill Baird

[Gary Schisler]

Re: oil

As the other posts have stated, new technology oil is great for your car. In addition, I have been using synthetics in all of my cars for the last 20 years. Synthetics resist chemical breakdown (shearing) better than regular oil and they have far superior resistance to breakdown in high temps. Their pourability at cold temps is well proven too.

[Gary Schisler]

Re: oil

As the other posts have stated, new technology oil is great for your car. In addition, I have been using synthetics in all of my cars for the last 20 years. Synthetics resist chemical breakdown (shearing) better than regular oil and they have far superior resistance to breakdown in high temps. Their pourability at cold temps is well proven too.

[Jeff]

Re: oil

I've used Mobil 1 from Day 1 because I have always felt the chances that some dinosaur's rotting body happened to be the perfect lubricant for my car were slim. I use it in everything from trucks and heavy equipment to boats and lawn mowers and not just in the engine but in the entire drivetrain, on all wear surfaces and in all grease fittings. I'd probably drink it if Mobil recommended it.

I have heard the theory about increased oil leaks. I believe it has to do with the belief that synthetics do not 'swell' or 'bloat' seals and gaskets as much as conventional oil. I do think I notice that synthetic grease seems to have more of a tendency to squeeze past old-tech seals like the CV joint seals in a CJ2A but I haven't experienced any new oil leaks in millions of miles and decades of switching used vehicles to Mobil 1. However, I do believe it is possible to cause increased oil consumption by breaking in certain engines with synthetic oil. My experience has been that some types of rings are reluctant to wear-in on Mobil 1. My practice is to break in any engine not originally speced for synthetics with the best conventional oil recommended for that application until the first oil change then switch.

Synthetics do get as dirty as conventional oils but the filter takes care of that. You don't have to change synthetic oil at the same intervals as those required by conventional oil as long as you use a good quality filter and change *it* at the recommended interval. Last I looked, Mobil recommended 25,000 miles between oil changes if you change the filter every 5000 miles. Synthethic oil and a quality filter are an unbeatable combination. I have always used Hastings filters but I see that Mobil now has a filter designed specifically for Mobil 1. Good filters cost 5 times as much as the cheapies but remember, 'if you pay peanuts, you get monkeys'.

The 2 things that degrade oil are dilution by gasoline (or diesel) and excessive temperature. The contamination usually occurs from cold starts so you can generally go longer between oil changes in the summer than the winter. Also with electronic chokes providing a less rich mixture on start-up and leaning out the mixture sooner, dilution does not occur as frequently as it used to. If the dilution is caused by a wear (although the rings are often blamed, the bearings are usually the culprit) you have to adjust the change interval by inspecting the oil. Over-temperature shouldn't be an issue with synthetics unless you seriously overheat the engine.

Synthetics don't form varnishes when they sit for long periods like conventional oils so they are the perfect choice for 'occasional use' vehicles like collector cars. Another benefit is that they don't smoke in an engine that burns oil (but most have a sweet smell you can detect at the tailpipe when they are being combusted) and they may actually reduce oil consumption. Cold cranking is improved as well as engine cooling especially in applications with a remote cooler.

FWIW, you can often reduce the amount of oil you put in the crankcase to save money and/or reduce oil drag. I use 4 qts in most applications requiring 5 and I use 10 gallons instead of 12 in truck engines. If you monitor your oil consumption carefully you may find that an initial amount of oil is generally burned off in the first couple of hundred miles and then stabilizes, not consuming any more (or very little) prior to the next scheduled change. If you are going to try this be sure to stay on top of it until you are extremely familiar with your engine's oil drinking habits.

JP

[Jeff]

Re: oil

I've used Mobil 1 from Day 1 because I have always felt the chances that some dinosaur's rotting body happened to be the perfect lubricant for my car were slim. I use it in everything from trucks and heavy equipment to boats and lawn mowers and not just in the engine but in the entire drivetrain, on all wear surfaces and in all grease fittings. I'd probably drink it if Mobil recommended it.

I have heard the theory about increased oil leaks. I believe it has to do with the belief that synthetics do not 'swell' or 'bloat' seals and gaskets as much as conventional oil. I do think I notice that synthetic grease seems to have more of a tendency to squeeze past old-tech seals like the CV joint seals in a CJ2A but I haven't experienced any new oil leaks in millions of miles and decades of switching used vehicles to Mobil 1. However, I do believe it is possible to cause increased oil consumption by breaking in certain engines with synthetic oil. My experience has been that some types of rings are reluctant to wear-in on Mobil 1. My practice is to break in any engine not originally speced for synthetics with the best conventional oil recommended for that application until the first oil change then switch.

Synthetics do get as dirty as conventional oils but the filter takes care of that. You don't have to change synthetic oil at the same intervals as those required by conventional oil as long as you use a good quality filter and change *it* at the recommended interval. Last I looked, Mobil recommended 25,000 miles between oil changes if you change the filter every 5000 miles. Synthethic oil and a quality filter are an unbeatable combination. I have always used Hastings filters but I see that Mobil now has a filter designed specifically for Mobil 1. Good filters cost 5 times as much as the cheapies but remember, 'if you pay peanuts, you get monkeys'.

The 2 things that degrade oil are dilution by gasoline (or diesel) and excessive temperature. The contamination usually occurs from cold starts so you can generally go longer between oil changes in the summer than the winter. Also with electronic chokes providing a less rich mixture on start-up and leaning out the mixture sooner, dilution does not occur as frequently as it used to. If the dilution is caused by a wear (although the rings are often blamed, the bearings are usually the culprit) you have to adjust the change interval by inspecting the oil. Over-temperature shouldn't be an issue with synthetics unless you seriously overheat the engine.

Synthetics don't form varnishes when they sit for long periods like conventional oils so they are the perfect choice for 'occasional use' vehicles like collector cars. Another benefit is that they don't smoke in an engine that burns oil (but most have a sweet smell you can detect at the tailpipe when they are being combusted) and they may actually reduce oil consumption. Cold cranking is improved as well as engine cooling especially in applications with a remote cooler.

FWIW, you can often reduce the amount of oil you put in the crankcase to save money and/or reduce oil drag. I use 4 qts in most applications requiring 5 and I use 10 gallons instead of 12 in truck engines. If you monitor your oil consumption carefully you may find that an initial amount of oil is generally burned off in the first couple of hundred miles and then stabilizes, not consuming any more (or very little) prior to the next scheduled change. If you are going to try this be sure to stay on top of it until you are extremely familiar with your engine's oil drinking habits.

JP

[Doug Flaten]

Re: oil

You can find an explanation of the API oil rating system @ http://www.api.org Look under consumer information and it has historical oil grades as well as some advice. I use mineral oil in my vehicles but change it often. However, I do believe the synthetics are superior. However, I would not stretch the service interval on the oil changes to long intervals such as Mobil's claim of 25,000 miles unless I was doing some sort of continuous oil analysis program which would cost you more to do work than another oil change would. Keep in mind that those inflated oil change intervals were developed using modern, cleaner fuel injected cars with tighter tolerances that do not contaminate the oil nearly as much as the older carbuerated cars. The contaminants are going to dilute the synthetics just as they do the mineral based oils. The difference is that they will not break down or form deposits as readily. Since one of the functions of oil is cooling engine components, I would not reduce the oil capacity just to save a few bucks on the oil change.

[Doug Flaten]

Re: oil

You can find an explanation of the API oil rating system @ http://www.api.org Look under consumer information and it has historical oil grades as well as some advice. I use mineral oil in my vehicles but change it often. However, I do believe the synthetics are superior. However, I would not stretch the service interval on the oil changes to long intervals such as Mobil's claim of 25,000 miles unless I was doing some sort of continuous oil analysis program which would cost you more to do work than another oil change would. Keep in mind that those inflated oil change intervals were developed using modern, cleaner fuel injected cars with tighter tolerances that do not contaminate the oil nearly as much as the older carbuerated cars. The contaminants are going to dilute the synthetics just as they do the mineral based oils. The difference is that they will not break down or form deposits as readily. Since one of the functions of oil is cooling engine components, I would not reduce the oil capacity just to save a few bucks on the oil change.