Mobil 15 - 50 is my choice. No problems so far. If it was 20 degrees out, I would change out to Mobil 0-40. Both have adequate zinc levels. The oil conspiracy will never end. If you are running a certain brand of oil and you have no issues with it, than that is the right oil to run in your engine.
Mobil has a nice chart available on their website, detailing the specifications of their line of oil products.

 

I am located in Florida so we rarely see cold temps.

 

The problem with the oil argument that someone has not a a problem with "such and such oil using such and such grade viscosity or diesel oil and all is good" is that unless their is a major engine problem, 99% of folks have no idea what is happening internally to their engine until the engine is taken apart after so many miles or years to directly observe wear patterns or no wear. When I took apart my L-82 in march this year and saw the L-82 cam and lifters after using Mobil 1 since 1986, I was astonished by the lack of wear with 3.70 gears and observed the cylinder walls which looked remarkable as well. I had the same experience about 2 years ago replacing a head gasket on my Kohler tractor which has used Mobil 1 since it was new in 1997 (about 2,500 hours) and the cylinder wall still shows the cross hatch mark. Most oils will prevent the engine from blowing up but the difference is in the details-wear patterns-which can be hugh between different types of oils.

 

mobil 15w 50w. The original weight oil for a 68 was much less. Is the increased viscosity a problem?

 

It could be. Depends on the bearing clearances in your engine.

 

You'll never get a consensus of any type. No matter what's suggested as a brand, type, viscosity- whatever, there'll always be somebody who will come up with a horror story.

If the sticky didn't completely confuse you, another post on the subject won't help.

Good luck!

 

All I can tell you is that in my 78 L-82 4 speed the recommended oils are as follows-straight from the owners manual which I still have:

-20 to 20 degrees: 5W-20
-20 to 60 degrees: 5W-30
0 to 60 degrees: 10W
0 to above 100 degrees: 10W-30, 10W-40
20 to over 100 degrees: 20W-20, 20W-40, 20W-50
40 to over 100 degrees: Straight 30

From the manual-footnote-"Notice, do not use SAE 5W-20 oils for continuous high speed driving."

Bottom line is you can use just about any Viscosity oil according to GM back in 1978-not even today where oils are FAR superior! NONE of the above recommendations for temperature ranges apply for a SYNTHETIC OIL which are VASTLY superior to the conventional oils that only existed back in 1978.

There is VERY little chance that a 15W-50 will hurt the engine-nonsense! In fact, the older the engine and more mileage the more likely that a higher viscosity oil (20W-50) would be BETTER. My brand new L-82 rebuilt is currently running 20W-50 Driven oil per the builders direction for the first 250-500 miles. Going to Mobil 1 0W-40 after that-roller cam.

My 2001 Pontiac Grand Prix that does mostly high speed driving-75+ has Mobil 1 0W-40 with 160,000 miles on the motor-zero oil consumption between 5,000 miles oil change intervals. GM recommends 10W-30-has not had that oil for over 110,000 miles. Much too much is made about the viscosity of the oil to use as long as the right oil is used for the temperature outside-really below 0. Synthetic oils make most of these discussion irrelevant. Many years ago during winter, I put a conventional oil 10W-30 and Mobil 1 20W-50 (no longer made) at 0 degrees, then tried to pour both once they had been exposed to the 0 degrees overnight-the Synthetic poured almost like water (20W-50) and the conventional 10W-30 poured like Molasses-so much for viscosity!

BTW- a 68 350 and a 78 350 are the essentially the same engines from GM.

 

Does anyone have their oil analyzed? Wouldn’t that be a good way to determine wear characteristics on an oil?

 

I use Valvoline VR-1 10w30 conventional oil in all of my cars (they're all flat tappet engines). The mechanic that built the engine in my 79 Vette and 72 Buick GS455 recommends VR-1 (though he uses the more readily available 20w50, but I drive the cars all year), it has high levels of ZDDP, is designed for flat- tappet engines, and is the highest ranked non-racing oil on 540 RAT's list. (Even though marketed as a racing oil, it is designed for 3,000 mile oil change intervals.) So, it's a top choice on both sides of the discussion. The synthetic VR-1, if I recall correctly, is ranked just under the conventional VR-1 on 540 RAT's list, so it's a good choice for a synthetic oil to use.

 

Does anyone know where Valvoline VR-1 can be purchased from in Canada? More specifically in Alberta?

 

The only credible way of using analysis is by taking samples on a regular scheduled basis and trending the results. After a baseline indicating what's 'normal' for a given engine is established, variations in subsequent samples can help indicate impending problems.

A single isolated sample is virtually useless.

 

Here in town, I can grab it right off the shelf at my local NAPA.


https://valvoline.com/products/consu...ng-motor-oil/6

 

I order it in cases of 6 quarts from amazon.

 

Ever try shipping oil across an international border??????

 

I checked with our local Napa and they only carry 20w50. I think that viscosity is too much for a street driven vehicle. For some reason they don't have information about purchasing Valvoline Vr-1 10w30. Odd...

 

That's what I'm using. Original L48 with 144,000kms on her. I figure if anything, it may help those old bearings........never had a problem, and it lists 20W50 as an acceptable oil in my owners manual.

 

Same for me....VR-1 10w30 conventional by the case from Amazon.

 

I saw a number of you use Valvoline VR-1 so I was curious as to why? I looked up VR-1 on Valvoline's website expecting this oil to have super high ZDDP but found that it was the same as Mobil 1's 15W-50-1,200/1,300 Zinc/Phosphorous AND was a conventional oil. No really sure why anyone would use a conventional oil anymore-just me- when synthetics have been shown to be vastly superior to conventional oils in every respect. The difference between a 10W weight oil and 15W weight is negligible and the 50 of Mobil 1's index indicates an oil with vastly superior high temperature protection versus a 30 weight oil. I am just trying to understand why folks chose oils especially when a quality synthetic like Mobil 1 15W-50 can be had for a relative bargain at Walmart for $25 for 5 qts. I am sure Valvoline VR-1 is also a quality conventional oil but seems to be a lot of effort to get it in some areas. Maybe the racing association in the name?

For those not informed about Mobil 1 15W-50, it is used not only for street performance vehicles and specifically recommended by Mobil for engines with flat tappet cams but also in racing-Check the oil sticky for the All about Oils article.

From the back of Mobil 1 15W-50 container:

"Mobil 1 15W-50 is a race proven product (this is true) and suitable for a wide range of motorsports applications including sprint and endurance racing on both circle and road tracks.Used by grassroots racers as well as professionals in a wide range of race series including ALMS, NASCAR and Grand Prix racing (Formula 1)."

Are there better Synthetics than Mobil 1? Absolutely yes (Amsoil comes to mind and Royal Purple) but they cost about 50% more than Mobil 1 15W-50. In fact, Molbil 1 0W-40 European Formula (A true Group IV synthetic) is better but I reserve recommending for flat tappet cammed engines since it has 1,000 PPM ZDDP.

My totally rebuilt L-82 currently has Driven CONVENTIONAL 20W-50 per the bottom end builders recommendation and I will be switching to Mobil 1 0W-40 EURO AT 250 miles on the new engine (roller cam). I have used a synthetic in the 78 since 1986…..

 

i use the VR1 synthetic, mostly because of availability.

 

No need to doubt you jb, I'm sure the Mobil 1 is a great product - as are Amsoil and Royal Purple in their own right. My problem my friend is I can't buy them north of the border (OK, I could get Royal Purple....but the closest distributor is 85 miles away, and charges $18 a litre). There are Mobil 1 oils sold at my local Wally World, but not what you're recommending. Just check Walmart Canada's website and you'll see what I mean.


Even sourcing the 30 weight VR1 here has become a nightmare. The NAPA's in Toronto (100 miles away) are able to order - at a premium, and it can take up to 3 weeks to get it. My town is only 17,000 people and almost 75% of the items I need to keep my car hobby alive have to be shipped from your beautiful country. Don't even get me started with shipping costs, 13% sales tax, duty, and an ever changing exchange rate. I wish some days I could just drive down to Buffalo, stay the week and get everything that I want to do done at once.......but alas, the wonderful border agents tend to frown on that approach. I really do envy you guys that can call up Summit and have a long block shipped from Miami to Seattle free of charge, that can head to a shopping centre and buy car parts and tools for 1/4 of what it costs us. Don't get me wrong, I still love where I live and I wouldn't trade places with you for anything........but sometimes you just gotta play the cards your dealt as well as you can. Happy motoring.