I'm trying to figure out how much B20 (only mix avail in my area) I can put in a 29 gal tank and not blow Ford's B5 limit. Are these calc's correct?

Assumptions:

• B20 = 20% BD / 80% Petro (0.25)
• B5 = 5% BD / 95% Petro (0.05)
• 29 gal total

Calculations:

1. 0.25X = 0.05
2. X = 0.05/0.25 = 0.20
3. 29(0.20) = 5.8 gal of B20

So, I could put 5.8 gal of B20 + 23.2 gal of pure petro diesel into an empty 29 gal tank and be within Ford's limit, right?

Thanks...