As with any tool the measures, it's a good idea to calibrate it every so often if possible. Every time I get any tire work done on any of my vehicles I take my 1/2 inch with me. "Good enough for me" is to re-check what they torqued to with my torque wrench to see if torque numbers match. My 1/2 inch has been right on since day one. I also take my air pressure gauges with me also.
But my 1/4 inch harbor freight torque wrench, not so good. I actually broke the bolt on my thermostat housing. The 1/4 inch wrench was way off. Next one I get from them I'm going to "calibrate" it the second I get it home. And return it if not right.
Just curious if shops such as CW or RV dealers actually torque these wheel lugs or do they just use an impact wrench, or do impact wrenches have torque adjustments on them?
Little bit of all the above IMO. My tire shop uses manual torque wrenches that they have calibrated once a quarter by a third party.
Surprisingly my local Discount tire and Les Schawb do not have a "calibrated" air pressure gauge. The air they do put in is "drawn from an air compressor with a quality air pressure gauge on air tank, so no problems" Wrong IMO. My black and decker air compressor gauge is accurate (or three other neighbors are off also)
What really drives me nuts... is the tire shops around me don't look up what the OEM states what the lug nut torque should be. They pull a number out of their head. On my 1 ton ford, the torque is stamped on the lugs. Other 3 vehicles are not marked. I took the time to look up what OEM states what the lug nut torque should be. Then I wrote down the torque spec's on a 3x5 card, and keep that card in the plastic torque wrench holder to refer to. So no guessing.
My local Les Schawb manager knows me by now. When he sees me, he smiles and says..."let me guess, DOT codes out, air pressure and torque to customer spec's"
And when your buying tires read if they "rotate" for free or if they "rotate and balance" for free. Most just rotate but every other rotation (7,500 miles) I get them to balance.
OK, I've been told I'm only anal about a couple things in life, torque is one of them:)