Outlaw,
I'd run the Mobil 1, 0w-20 in the Accord due to the short trip driving conditions, which will give you a small fuel savings and better engine response during the warmup phase. In the CRV, I'd run the Mobil 1, 10w-30, which is their best formulation for high temp use.
The 0w-20 has a HT/HS of 2.6 Cp, compared to 3.3 Cp for the 10w-30, so the 10w-30 is about 20% thicker. The HT/HS viscosity is directly related fuel efficiency ....For example, the Series 3000, 5w-30 has a HT/HS of approx 3.5 Cp, compared to 4.2 Cp for the Amsoil 15w-40. That's good for a fuel savings of approx 3% under steady state conditions....You'll see a comparable fuel savings; using the 0w-20 instead of the 10w-30.
Tooslick
Dixie Synthetics