Okay, every good forum has to have an oil thread. This is it.
As we all know, our RS's require 5W-50. If you go into your local Walmart, Autozone or O'Reilly's auto parts store, you will not find ANY 5W-50 oil. NAPA can order a few. So there must be alternatives.
First, not all oils of the same *advertised* weight are equal. You might have a 0W-40 from one manufacturer that is "thicker" than a 5W-50 from another. So if you want to compare apples to apples you have to look at the oil specifications of viscosity and also HTHS (High Temperature High Shear). Viscosity is measured in centistokes (CsT). The higher the number, the thicker the oil. HTHS is a rating that determines the oil's stability in a high temperature, high stress conditions. The higher number the better.
Here is a list of oils that I could find, and the cheapest prices I could find and US retailers for 5W-50 oils:
Motorcraft synthetic, O'Reilly Auto Parts, $10.19/qt
Castrol Edge synthetic, O'Reilly Auto Parts, $9.19/qt
Mobil 1, Amazon.com, $51.56 for 6 quarts and free shipping ($8.59/qt)
Redline, Redline.com, $51.95/gal (12.99/qt)
Easy alternative:
Shell Rotella T6 5W-40, Walmart, $19.57/gal
This is a list of some popular (and some not so popular in the US) oils and their specifications:
*
For what it's worth, based on this data, MY choice is the Redline 5W-40. It has relatively low viscosity when cold (<100), higher viscosity when hot (>15), and a good HTHS (~4.5). Although the 5W-50 oils have great viscosity when hot, they are all just too damned thick to pump at lower temps, and for a daily driver, that's not acceptable to me.
If you have any changes or additions, please PM me and I will update the table.
As we all know, our RS's require 5W-50. If you go into your local Walmart, Autozone or O'Reilly's auto parts store, you will not find ANY 5W-50 oil. NAPA can order a few. So there must be alternatives.
First, not all oils of the same *advertised* weight are equal. You might have a 0W-40 from one manufacturer that is "thicker" than a 5W-50 from another. So if you want to compare apples to apples you have to look at the oil specifications of viscosity and also HTHS (High Temperature High Shear). Viscosity is measured in centistokes (CsT). The higher the number, the thicker the oil. HTHS is a rating that determines the oil's stability in a high temperature, high stress conditions. The higher number the better.
Here is a list of oils that I could find, and the cheapest prices I could find and US retailers for 5W-50 oils:
Motorcraft synthetic, O'Reilly Auto Parts, $10.19/qt
Castrol Edge synthetic, O'Reilly Auto Parts, $9.19/qt
Mobil 1, Amazon.com, $51.56 for 6 quarts and free shipping ($8.59/qt)
Redline, Redline.com, $51.95/gal (12.99/qt)
Easy alternative:
Shell Rotella T6 5W-40, Walmart, $19.57/gal
This is a list of some popular (and some not so popular in the US) oils and their specifications:
| BRAND | TYPE | cSt @ 40 C | cSt @ 100 C | HTHS |
| Motorcraft | 5W-50 | 136 | 21 | ??? |
| Castrol Edge | 5W-50 | 114.36 | 18.5 | 3.7 |
| Redline | 5W-50 | 130 | 21.0 | 5.0 |
| Mobil 1 | 5w-50 | 108 | 17.5 | 4.4 |
| Amsoil | 5w-50 | 127 | 20.3 | 4.7 |
| Pennzoil Platinum | 5w-50 | 106 | 17.8 | 4.1 |
| Schaeffer 9000 | 5w-40 | 85-89 | 13.50-15.75 | 4.5 |
| Motul 300V | 5w-40 | 80.8 | 13.8 | 4.51 |
| Motul 300V | 10w-40 | 89.5 | 14.0 | 4.2 |
| Motul 300V | 15w-50 | 128.1 | 17.8 | 5.33 |
| Redline | 5w-40 | 97.0 | 15.6 | 4.4 |
| Redline | 10w-40 | 93.0 | 14.6 | 4.7 |
| Mobil 1 | 0w-40 | 78.3 | 14.0 | 3.7 |
| Mobil 1 | 5w-40 | 83.0 | 14.0 | 3.6 |
| Fuchs Titan Supersyn | 5w-40 | 86 | 14.2 | |
| Amsoil | 5w-40 | 79.7 | 13.7 | 3.7 |
| Amsoil | 10w-40 | 90.5 | 14.6 | 4.3 |
| Elf HTX | 5w-50 | 117.0 | 19.3 | 4.6 |
| Total Quartz | 5w-40 | 82.3 | 13.6 | |
| Shell Rotella T6 | 5w-40 | 87 | 14.2 | 4 |
| Royal Purple | 5w-40 | 93.7 | 15.7 | 3.91 |
| Chevron Delo 400LE | 5w-40 | 88.5 | 14.6 |
For what it's worth, based on this data, MY choice is the Redline 5W-40. It has relatively low viscosity when cold (<100), higher viscosity when hot (>15), and a good HTHS (~4.5). Although the 5W-50 oils have great viscosity when hot, they are all just too damned thick to pump at lower temps, and for a daily driver, that's not acceptable to me.
If you have any changes or additions, please PM me and I will update the table.
