Tom,
I bought a '92 Dolphin V6 auto in Oregon and drove it home to Colorado. No problems flat road 75 EZ, looong steep mountains about 35 but so were the truckers (even passed a couple). Couple weeks ago Went down to La Veta on 25 Avg 16MPG.
Terry
When I was ckecking my system (one side would not hold air ) I could not find the leak. It turned out There was to much pressure in the system and the soapy water was vaporized before I could see the bubbles. with the system almost airless I found the leaky hose.
Terry