This is a bit odd...
looked into it further, on the Mobil 1 website and found this:
Mobil 1 regular formula:
Mobil 1 5W-30
SAE Grade 5W-30
Viscosity, ASTM D 445
cSt @ 40º C 64.8
cSt @ 100º C 11.3
Viscosity Index, ASTM D 2270 169
Sulfated Ash, wt%, ASTM D 874 1.0
HTHS Viscosity, mPa·s @ 150ºC ASTM D 4683 3.09
Pour Point, ºC, ASTM D 5949 -48
Flash Point, ºC, ASTM D 92 230
Density @15º C kg/l, ASTM D 4052 0.80
and, Mobil 1 Truck and Suv formula:
SAE Grade 5W-30
Viscosity, ASTM D 445
cSt @ 40º C 64.8
cSt @ 100º C 11.3
Viscosity Index, ASTM D 2270 169
Sulfated Ash, wt%, ASTM D 874 1.0
HTHS Viscosity, mPa•s @ 150ºC ASTM D 4683 3.09
Pour Point, ºC, ASTM D 97 -54
Flash Point, ºC, ASTM D 92 230
Density @15º C kg/l, ASTM D 4052 0.86
In the specs, it appears as though the truck and suv formula has a lower pour point, identical viscosity and cst's, identical HTHS, with a slightly higher density at 15Celcius - 0.86 vs 0.80 for the regular formula...
With all that in mind, where are the benefits for a truck or suv hauling a load? Only in the density? The HTHS is identical, and the sulfated ash percentage being identical suggests a very similar overall formula, unless I'm missing something else...