This has been a very helpful thread!
I want to pick up on the comments about compressors, even though it's a bit off the original "jack" topic. I have a Viair 880P which is way underpowered for my tires. I think I'll retire it to the trunk of my car, and maybe use it to blow up beach balls. If I had any beach balls. I'm looking at the high-end Viair 12-V compressors like the model 40047 440P/RV, which seem to get great reviews on Amazon. They're darn expensive: $236 this morning on Amazon. I'm also looking at "portable" 120V compressors: the Porter-Cable CMB15 is listed at $99 this morning on Amazon. I have a generator. I'm often parked overnight someplace with shore power. 10Amps. Either in camp, or on the road, I'm thinking that if I have the storage space, the 120V AC unit is a much better purchase.
Peter-Cable is spec'd at 150 psi, 2.0CFM at 90 psi.The Viair lists 150 psi and 2.54 CFM at 0 PSI.
P-C listing says it's 15X30X10 inches. Viar is 12X4X7 in its case.
Comments?