Ideas? DPF, but then I am paranoid of it.

Flow resistance is a square function of velocity, and flow volume rate should be linear with engine speed RPM IIRC. Flow resistance is linear with flow area, the hypothetical clogging of the DPF.

Friction = 1/2 (density) (velocity squared) (shape coefficient) (flow X-section area)

Full weight versus empty weight is acceleration (F=m a), not top speed. Top speed is all drag, the same relation as above.

Cold bearings is good. For long term unpowered bearing condition, look at its tire.

Best wishes. We're at thirty-five days until we head south to Seabrook Island, SC and Inverness, Florida.

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