My local Autozone has quit carrying 20w50 motor oil that I run in my engine and had it reduced to $2 a quart, so I bought all they had left. I typically run VR1 oil which has some zinc it in, but I bought some reg Valvoline oil and would like a zinc additive to put in with the oil. The car is only street driven, but has a hydraulic flat tappet cam. What additive are you guys using?

Go to E-Bay.com and search for ZDDP. Lots of sellers with all kinds of prices.

I've always used GM EOS. people have said (on here) that it is better to just use an oil with enough zinc as mixing/matching additives can play havoc with the chemistry but with you have the oil in hand I would not sweat using an additive.

Rislone ZDDP additive $10 at O reilly.

Same here as I pick up Risoline zinc additive at Pep Boys. Ron

Why do you need to run 20 50 in a street engine? Do you have a over heat issue, bearing clearance? I have always run 30 in both my street and race engines (dyno 817 hp) and have never had a problem. I'm not criticizing, just wondering.

I use Kendall 10-40 and STP. Has never let me down and I've used it for cam break in as well. Maybe I've just been lucky, but the combo was recommended by a Chrysler technician.

Thanks for the info. As for why I use 20w50, my dad used to use straight 40, but that's almost impossible to find and we started to use 20w50. This is an old race motor of ours that we stuck in my street car. Its what we used in it when we raced it without any issues so just stuck with the 20w50.

Brad Penn

I recently switched to Valvoline VR-1 because several people said it's better for the zinc content vs conventional 10W30. I got a great deal on Amazon on it and that's one reason I got it. Now it's crazy expensive. I was thinking of adding Risoline zinc additive to conventional oil, but only about half a bottle. Do you just add it, or do you replace the oil with it? Or would 5.5 oz not make much of a difference anyway? I never added zinc since we got the car in 2005 and no issues with it either. Just using zinc sounded like a bit of insurance per say. I think half a bottle will put the conventional just about where the VR-1 is at or slightly below it. I don't put a bunch of miles on the car and change the oil when it comes home from storage and when it goes into storage.

I would sooner buy a proper oil. From what I've read, adding too much zddp can be detrimental to lubrication including cam wear.

Ditto. I was told by a lubricant engineer that additives will fall out of suspension and settle in the pan as well.

Brad Penn (1500PPM) is used by a large percent of high dollar engine builders, and is cheaper than VR1 (1200PPM).

Any oil with zinc in it, had the zinc additive put in it...

been using the zddp additive for many years...I add the 4 oz bottle into the one gallon jug of oil...shake it....done..

Exactly.

Adding it after the product is finished is different than adding it during the manufacturing process.

Why would anyone run an oil they have to buy a $4-$10 addative for, when they could buy an oil that already has it?

I run VR-1 in a mild 440 with stock hydraulic flat tappet - over 20 years - no additives, no problems

Also VR-1 used in my 500HP 408 stroker SB, solid flat tappet - used for the last 4 years - no additives, no problems

I used Brad Penn in the 408 for the first year, but it would use a half quart between changes, switched to VR-1, all is good

Brad Penn always seems a lot thicker than what the viscosity is showing on the label, and seems "stringy" when you pour it in, compared to my other brands

For those of you who use VR1, are you using the synthetic, or conventional?

That's good to know. I also find that BP 5W-30 and 0W-30 requires topping off between oil changes (about 2000 - 2500 miles).

Relative evaporation between oils can compared using the volatility test results. Sometimes the NOACK volatility for can be found on spec sheets and almost always the Flash Point. The flash point is obviously a less direct correlation to the evaporation rate but its better than nothing. Volatility can vary between grades as well as between brands.

The actual thickness (viscosity) of any oil can be usually found on the manufacture's spec sheet. Richard Widman has an on-line calculator that can be used to show the viscosity at any temperature given viscosity at the two standard temperatures on those sheets. Graph & Table for up to 4 Oils Actual oil viscosity definately varies with the allowable limits of the grade.

My local Autozone did the same. Found out recently when trying to buy some. Bought some today from NAPA, they had it on sale. I like it for some high mileage vehicles I have for the added thickness.

This what I use in my HP69 440 I RUN THE 20/50 In the summer and the 10/30 in the winter when car is stored , I like to start mine once a month and garage is cold