Here are the 13 Diesel Oils that were tested by 540Rat. And they are ranked in the order
of their “Load Carrying Capacity/Film Strength” values:
1. RED LINE, 15W40 Diesel Oil, synthetic, API CJ-4/CI-4 PLUS/CI-4/CF/CH-4/CF-4/SM/SL/SH/EO-O
“Load Carrying Capacity/Film Strength” = 85,663 psi
zinc = 1615 ppm
phos = 1551 ppm
moly = 173 ppm
total detergent/dispersant/anti-deposit build-up/anti-sludge = 2999 ppm
TBN = 8.3
The onset of thermal breakdown is approximately 285*
2. ROYAL PURPLE, 15W40 Diesel Oil, synthetic, API CJ-4 /SM, CI-4 PLUS, CH-4, CI-4
“Load Carrying Capacity/Film Strength” = 76,997 psi
zinc = TBD
phos = TBD
moly = TBD
total detergent/dispersant/anti-deposit build-up/anti-sludge = TBD
TBN = TBD
The onset of thermal breakdown is approximately 265*
3. MOBIL 1 TURBO DIESEL TRUCK, 5W40 synthetic, API CJ-4, CI-4 Plus, CI-4, CH-4 and ACEA E7
“Load Carrying Capacity/Film Strength” = 74,312 psi
zinc = 1211 ppm
phos = 1168 ppm
moly = 2 ppm
total detergent/dispersant/anti-deposit build-up/anti-sludge = 1596 ppm
TBN = 9.3
The onset of thermal breakdown is approximately 270*
4. CHEVRON DELO 400LE, 15W40 conventional, API CJ-4, CI-4 Plus, CI-4, CH-4, SM, SL, “Load Carrying Capacity/Film Strength” = 73,520 psi
zinc = 1519 ppm
phos = 1139 ppm
moly = 80 ppm
total detergent/dispersant/anti-deposit build-up/anti-sludge = 2205 ppm
TBN = 8.0
The onset of thermal breakdown is approximately 265*
5. MOBIL DELVAC 1300 SUPER, 15W40 conventional, API CJ-4, CI-4 Plus, CI-4, CH-4/SM, SL , “Load Carrying Capacity/Film Strength” = 73,300 psi
zinc = 1297 ppm
phos = 944 ppm
moly = 46 ppm
total detergent/dispersant/anti-deposit build-up/anti-sludge = 1843 ppm
TBN = 9.8
The onset of thermal breakdown is approximately 250*
6. Farm Rated 15W40 Heavy Duty Performance Diesel, conventional, API CI-4, CH-4, CG-4, CF/SL, SJ
“Load Carrying Capacity/Film Strength” = 73,176 psi
zinc = 1325 ppm
phos = 1234 ppm
moly = 2 ppm
total detergent/dispersant/anti-deposit build-up/anti-sludge = 1593 ppm
TBN = 9.3
The onset of thermal breakdown is approximately 255*
7. SHELL ROTELLA T, 15W40 conventional, API CJ-4, CI-4 Plus, CH-4, CG-4, CF-4,CF/SM
“Load Carrying Capacity/Film Strength” = 72,022 psi
zinc = 1454 ppm
phos = 1062 ppm
moly = 0 ppm
total detergent/dispersant/anti-deposit build-up/anti-sludge = 2886 ppm
TBN = 9.1
The onset of thermal breakdown is approximately 250*
NOTE: This new Rotella T has SIGNIFICANTLY MORE zinc than the OLD
Rotella T, NOT LESS as is often claimed. And these two Rotella oils
were Lab tested more than a month apart. So, their component
quantities had no chance of being mixed up. This new Rotella’s wear
protection capability is just slightly BETTER than the OLD Rotella.
Therefore, the new Rotella is NOT the junk some have claimed.
8. “OLD” SHELL ROTELLA T, 15W40 conventional, API CI-4 PLUS, CI-4, CH-4,CG-4,CF-4,CF,SL, SJ, SH
“Load Carrying Capacity/Film Strength” = 71,214 psi
zinc = 1171 ppm
phos = 1186 ppm
moly = 0 ppm
total detergent/dispersant/anti-deposit build-up/anti-sludge = 2715 ppm
TBN = 10.1
The onset of thermal breakdown is approximately 250*
NOTE: There is ABSOLUTELY NOTHING special about this OLD Rotella, as
so many have always claimed. That was only folklore. It is simply
ordinary Diesel oil.
9. VALVOLINE PREMIUM BLUE HEAVY DUTY DIESEL, 15W40 conventional, API CJ-4, CI-4 Plus, CI-4, CH-4, CG-4, CF-4, CF/SM
“Load Carrying Capacity/Film Strength” = 70,869 psi
zinc = TBD
phos = TBD
moly = TBD
total detergent/dispersant/anti-deposit build-up/anti-sludge = TBD
TBN = TBD
The onset of thermal breakdown is approximately 255*
10. CHEVRON DELO 400LE, 5W40 synthetic, API CJ-4, CI-4 Plus, CI-4, SL, SM,
“Load Carrying Capacity/Film Strength” = 69,631 psi
zinc = TBD
phos = TBD
moly = TBD
total detergent/dispersant/anti-deposit build-up/anti-sludge = TBD
TBN = TBD
The onset of thermal breakdown is approximately 255*
11. SHELL ROTELLA T6, 5W40 synthetic, API CJ-4, CI-4 Plus, CI-4, CH-4, CG-4/SM
“Load Carrying Capacity/Film Strength” = 67,804 psi
zinc = TBD
phos = TBD
moly = TBD
total detergent/dispersant/anti-deposit build-up/anti-sludge = TBD
TBN = TBD
The onset of thermal breakdown is approximately 260*
12. LUCAS 15W40 MAGNUM Diesel Oil, conventional, API CI-4,CH-4, CG-4, CF-4, CF/SL
“Load Carrying Capacity/Film Strength” = 66,476 psi
zinc = 1441 ppm
phos = 1234 ppm
moly = 76 ppm
total detergent/dispersant/anti-deposit build-up/anti-sludge = 3393 ppm
TBN = 11.7
The onset of thermal breakdown is approximately 250*
13. CASTROL GTX DIESEL, 15W40 conventional, API CJ-4, CI-4 Plus, CI-4, CH-4, CG-4, CF-4/SN
“Load Carrying Capacity/Film Strength” = 66,323 psi
zinc = TBD
phos = TBD
moly = TBD
total detergent/dispersant/anti-deposit build-up/anti-sludge TBD
TBN = TBD
The onset of thermal breakdown is approximately 265*
The average value for Thermal Breakdown among the conventional Diesel
oils here, was 255*, which is 17* LOWER than among the conventional
gas engine oils I’ve tested.
The average value for Thermal Breakdown among the synthetic Diesel
oils here, was 267*, which is 15* LOWER than among the synthetic gas
engine oils I’ve tested.
And as you can see with these Diesel oils above, zinc levels alone do
NOT establish their wear prevention ranking. The zinc levels are
randomly up and down, relative to the ranking order. And as you will
see in the link to my motor oil ranking list below, zinc levels
clearly have NOTHING to do with an oil’s protection capability or
ranking order. Also, anyone who has followed my motor oil testing this
year, probably noticed that these Diesel oil “Load Carrying
Capacity/Film Strength” psi values are rather low, with an average
value for the whole group of only 72,408 psi. This number would put an
oil for gasoline engines, only in the MODEST PROTECTION category
(60,000 to 75,000 psi).
And considering that these oils are intended for use in heavy duty
working Diesel engines as used in big rigs, bulldozers, locomotives,
etc, etc, you probably expected to see some rather impressive psi
numbers. But, if you were expecting that, you were obviously
disappointed and maybe even shocked. So, what’s going on here?
Obviously since all these diesel oil numbers are so closely clustered
together with only about a 20,000 psi range (compared to the gas
engine oil numbers which have a much larger range of almost 60,000
psi), it is clear that the oil companies intentionally formulated them
to be in this general range. Why would they do that? How can that be
good enough for these hard working diesel engines?
Diesel engines of this type are made very rugged and very durable for
the long haul. And in order to accomplish that, the engine’s
components are designed and sized to keep the part loading at a modest
level. And of course, these engines are known primarily for their
impressive low end torque under boost, but NOT for their high rpm HP.
All that being the case, these oils don’t need to have a higher
capability. And this type of Diesel engine typically takes a LOT OF
OIL. So, cost becomes a real factor when changing oil. This means that
no oil company is going to make their products way better than needed,
because that would make their products too expensive to be competitive
in the marketplace.
And no one can complain that my test equipment and test procedure do
not allow high zinc oils to perform at their highest level. Because
here are some high zinc (over 1100 ppm) conventional, semi-synthetic,
and full synthetic gasoline engine oils that I’ve tested previously.
And they all had test results over 90,000 psi, which put them in the
“OUTSTANDING PROTECTION” category for gasoline engines.
10W30 Lucas Racing Only, full synthetic = 106,505 psi
zinc = 2642 ppm
phos = 3489 ppm
moly = 1764 ppm
10W30 Valvoline NSL (Not Street Legal) Conventional Racing Oil = 103,846 psi
zinc = 1669 ppm
phos = 1518 ppm
moly = 784 ppm
10W30 Valvoline VR1 Conventional Racing Oil (silver bottle) = 103,505 psi
zinc = 1472 ppm
phos = 1544 ppm
moly = 3 ppm
10W30 Valvoline VR1 Synthetic Racing Oil, API SL (black bottle) = 101,139 psi
zinc = 1180 ppm
phos = 1112 ppm
moly = 162 ppm
30 wt Red Line Race Oil, full synthetic = 96,470 psi
zinc = 2207 ppm
phos = 2052 ppm
moly = 1235 ppm
10W30 Amsoil Z-Rod Oil, full synthetic = 95,360 psi
zinc = 1431 ppm
phos = 1441 ppm
moly = 52 ppm
10W30 Quaker State Defy, API SL (semi-synthetic) = 90,226 psi
zinc = 1221 ppm
phos = 955 ppm
moly = 99 ppm
SUMMARY
Thermal Breakdown BEGINS SOONER with Diesel oil, than with gas
engine oils, which is not desirable for High Performance gas engine
usage. And as you can see by looking at this short list of “high zinc”
gas engine oils, or by looking at the complete ranking list below,
there are many, many gas engine oils available that are FAR SUPERIOR
to the best Diesel oils in terms of wear protection. Therefore, using
Diesel oils in high performance gas engines is NOT the best choice, if
you want superior wear protection with plenty of margin of safety
(extra reserve wear protection above what the engine typically needs).
For those who have used Diesel oil in High Performance gas engines for
years without issue, you were able to do that only because the wear
protection required by the engines, never happened to exceed the oil’s
capability. But, you were clearly running a MUCH LOWER margin of
safety than you would have been, if you’d used a much more capable gas
engine oil instead. So, if you’ve been using Diesel oil in High
Performance gas engines, you may want to rethink what you’ve been
doing and consider upgrading to one of the far better gas engine oils.
CONCLUSION
The bottom line is that the end user does NOT know more about motor
oil than the Oil Companies’ Chemical Engineers and Chemists. So, the
BEST choice is to use only quality gas engine oil in High Performance
gas engines. These oils offer MUCH HIGHER wear protection capability
and can withstand somewhat higher temperatures before the onset of
Thermal Breakdown. Leave the less capable Diesel oils for use only in
Diesel engines, where they are meant to be used.
