1986 740 Turbo: Looking for possible reasons for, get ready for a vague description, unknown drag like heavy feeling when driving. No audible hum sound, just a feeling of extra friction sapping the cars momentum in barely noticeable way. Also, my MPG is off 1 MPG or so, and that includes adjusting for winter gas.

Ruled out brakes. New reman calipers, new rotors, new rubber brake lines, pads, fluid both front and back. New, not rebuilt, master cylinder and reman brake booster.
Recently had trusted brake shop re-bleed and re-adjust brake booster. They checked heat of rotors and said it was in range after doing their repairs. So I trust the calipers aren't sticking and the brake system is working properly.

Probably rule out driveline, except axle, as in the last three years replaced the u-joints, centerline bearing, tailshaft bearing(?). These seemed to cause shudder and that's not what I'm describing here.

What I'm thinking: front wheel bearings are worn. New rotors are old one-piece style. (Yes, I know two-piece rotor is recommended but that's what happens when homework isn't done and get brakes replaced one-day before vacation. d'oh!...)

So the old bearings are in the new rotor, and who knows if they ever have been replaced at 235k miles.

or maybe the rear axle needs new oil? or is grinding apart?

Transmission? I thought it slips when it has a problem. Fluid level is good, actually a bit over filled.

Let me know what you all think!

p.s. If anyone wants to know more about my brake part sources and cost, I'm happy to share...
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