Now I know where empty is!

I just put 32.5 gallons in a 32 gallon tank. I was on fumes......! Needle covered red tick mark, wasn't below it. Our CNG vans were notorious for running out of 'gas'. On a cold morning you couldn't run it with 500psi (low), but you could wait until lunch and the thing would start and get you 1 mile down the road to the CNG station! We learned and then were told that you fill it up (3600 psi) at 1/2 tank, basically every other day. I put the LED needle on the fuel guage in my Lexus a little cocked so when I filled it up, it only showed 7/8 of a tank. I corrected it.