Valvoline VR1 - mixing viscosities

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7
Location
Oslo
Hi, I registered on this forum, because it seems to be the best place for oil related questions.

The car is a 1990 Porsche 944 S2.

I've been running Valvoline VR1 20w50 for 2-3 years. It works well in the spring/summer/fall and I've usually hibernated the car in winter. However, things have changed and now I need to use this car all year. Most days 20w50 is still fine, but the car is really unhappy about cold starts below freezing.

For my climate the ideal oil would be a 10w50, as it would work well both in the coldest and the warmest conditions I come across. 5wX is rumored to eat rod bearings due to being too thin on cold starts.

Valvoline does not have a VR1 10w50 (or 10w40), so I emailed them asking if I can mix their VR1 5w50 and their 20w50 to get something around 10w50. Their answer was that all VR1 oils are mixable. So I got a 4L bottle of VR1 5W50 and I notice it's a full synthetic. The 20W50 is not synthetic. That's when I start wondering if these oils are really compatible at all, or if their customer rep gave me the wrong advice.

If they were both dino or both synthetic I would have bought it, but now I'm getting suspicious - I'm suspecting that the additives in a synthetic would be quite different from the additives in a dino oil and that they won't work well together at all.

Any thoughts on this?
 
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1,929
Location
South Carolina
The add packs are pretty much identical, the base oil and VI content would be the biggest difference. If I was you though, I would just run the Valvoline VR1 5w-50 synthetic and not worry about trying to mix oils.
 

amelbye

Thread starter
Messages
7
Location
Oslo
The add packs are pretty much identical, the base oil and VI content would be the biggest difference. If I was you though, I would just run the Valvoline VR1 5w-50 synthetic and not worry about trying to mix oils.
The reason for not wanting to use 5w50 is the reports of 5w50 oils eating rod bearings in these engines.

Besides, I already have a few boxes of 20w50 on the shelf. I could always sell them on off course, but 5w50 is not ideal.

I'm not against changing brands, I just don't know of a good, affordable 10w50 with the right zddp content that is not a pure racing oil with 3month intervals....
 
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18,145
Location
Upper Midwest
The reason for not wanting to use 5w50 is the reports of 5w50 oils eating rod bearings in these engines.

Besides, I already have a few boxes of 20w50 on the shelf. I could always sell them on off course, but 5w50 is not ideal.

I'm not against changing brands, I just don't know of a good, affordable 10w50 with the right zddp content that is not a pure racing oil with 3month intervals....
The winter rating isn't going to eat bearings. Definitely not in Italy.
 

amelbye

Thread starter
Messages
7
Location
Oslo
the theory is that 5w and 0w oils are too thin on cold starts... No real science here, it's just based on the experience of a few race teams. 5w20 kills more rod bearings than 20w50 in these engines
 

amelbye

Thread starter
Messages
7
Location
Oslo
I think you should do some reading on what the winter rating actually means.
Winter rating means how thick the oil will be when cold. Lower number=thinner when cold. Thicker oils may compensate for the larger clearances in older engine designs. If I missed something, please tell me what I missed.
 
Messages
18,145
Location
Upper Midwest
the theory is that 5w and 0w oils are too thin on cold starts... No real science here, it's just based on the experience of a few race teams. 5w20 kills more rod bearings than 20w50 in these engines
It may be thinner but only at very cold temperatures but it’s still going to be massively thick. No oil is ever too thin at cold start up regardless of the winter rating. There is likely very little difference in viscosity between those oils at any reasonable temperature. Yes there is nothing quite some misunderstood is what the winter rating means and what it does not mean

And I think you mean 5W-50.
 
Messages
47
The reason for not wanting to use 5w50 is the reports of 5w50 oils eating rod bearings in these engines.

Besides, I already have a few boxes of 20w50 on the shelf. I could always sell them on off course, but 5w50 is not ideal.

I'm not against changing brands, I just don't know of a good, affordable 10w50 with the right zddp content that is not a pure racing oil with 3month intervals....
Used zddp oil additive like Rislone zddp which will higher zddp and used 5w50
 

SR5

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5,989
Location
Down Under
How about Mobil-1 15W50, a quality full synthetic with a strong zinc (ZDDP) add pack at 1300 ppm Zn. Plus it’s rated API SN and ACEC A3/B3.

It’s not a 5W50, which you don’t want. It will also start easier than a 20W50 in the cold.

If you can’t find the M1, my next choice would be Castrol Edge 10W60, it should be everywhere.

BTW your VR1’s, synthetic and mineral should mix fine.
 
Last edited:

amelbye

Thread starter
Messages
7
Location
Oslo
It may be thinner but only at very cold temperatures but it’s still going to be massively thick. No oil is ever too thin at cold start up regardless of the winter rating. There is likely very little difference in viscosity between those oils at any reasonable temperature. Yes there is nothing quite some misunderstood is what the winter rating means and what it does not mean

And I think you mean 5W-50.
Thanks for the input - so the bearing failures with 5w oils may just be coincidental...

Yes, I meant 5w-50.


Used zddp oil additive like Rislone zddp which will higher zddp and used 5w50
I'd rather use an oil that already has enough ZDDP - like the VR1 or the M1 15w-50.


How about Mobil-1 15W50, a quality full synthetic with a strong zinc (ZDDP) add pack at 1300 ppm Zn. Plus it’s rated API SN and ACEC A3/B3.

It’s not a 5W50, which you don’t want. It will also start easier than a 20W50 in the cold.

If you can’t find the M1, my next choice would be Castrol Edge 10W60, it should be everywhere.

BTW your VR1’s, synthetic and mineral should mix fine.
M1 15-w-50 is a god suggestion. However I'd have to order it from the US, as it's not sold in Europe for whatever reason.

The Castrol is 10w-60. My engine is rebuilt just 2 years ago, so I don't need a -60 oil. I could probably even use a -40 all year round.

For now I think I'll go with the mix. I have about 15 1L bottles of VR1 20w-50 on the shelf. That should last me about 5 oil changes if I mix in a 4liter 5w-50 each time, and give me something like 11.5W-50 which is spot on for all-year driving :)
 

amelbye

Thread starter
Messages
7
Location
Oslo
OP have you thought about an oil pan heater or dip stick heater?
In fact I was about to install a block heater last weekend. It's supposed to go into a threaded hole at the rear of the cylinder head, but the space back there is very tight and the plug currently in the hole was stuck. I can tell that some PO has been at it before and he probably gave up as well. I figured if I screw this up I may end up with the choice between taking the head off the engine or the engine out of the car, so I decided not to risk it. The options that remain are a heat pad under the oil pan or a heater on the dip stick. Those that connect to the coolant hoses are not an option as they're too close to the ECU temp sensor and will trick it into thinking the engine is warmer than it is, causing no-start.
 
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3,334
Location
Bolivia
Any thought that a 5W-50 causes bearing failure (rather than a 20W-50) is very false, unless the 5W-50 is a group III synthetic, where there may be serious shear of VI improvers. Put the specs in my graphing tool and you will see that in cold temperatures the 5W-50 is still way thicker (more viscous) than the optimum viscosity at temperature.
High rpm engines are very hard on viscosity improvers, and will shear many of them, so you need to use the top tier 5W-50 oils. Racing is tough on oils, as you have both high rpm and high temperature. So not only does it want to shear, but is often running out of its proper viscosity range. Here (Bolivia) most of the races are with Toyota or Honda engines, designed for 5W-30. I run 5W-50, as the winning cars come in with oil temps around 120. On the graphing tool, you can change the start temperature from 0ºC to 20ºC, and see what happens to the oil when you run 120ºC.
 
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7,484
Location
Roanoke Virginia
I’m sure it would be fine to mix them. I actually wasn’t aware they made the VR1 in anything except 10W-30 and 20W-50. I use the 20W-50 in my beetle at least in the summer I haven’t decided what to use in the winter.
 
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