A 240d should do a trip like that no prob.
Its done 250k miles so another 7 or 10k will be neither here nor there! Its not as though you are going on some dirt goat tracks 1000 miles from civilization!
Maybe take a second spare, with good tread. Flats like to occur in 2's.
A couple of spare fuel filters would be important if you are not using diesel.
Spare belts, radiator/heater hoses,injector return hose.
A few times I have broken the rubber exhaust mounts (rubber donuts) in the middle of no where, hay bailing poly twine wrapped around about 10 times & tied in a knot works well.
Make sure you cure any annoying squeaks or rattles before you leave.
Do the clutch before you go, would be worth checking the brake pads, extra weight = quicker ware. Change the gear box & diff oil before you go.
You will need to do a couple of oil changes on the trip, maybe take at least 10 quarts of engine oil.
don't worry about how fast you are going, The guy that passes you at 100mph, normally you find further down the road stopped with smoke coming out from under his car!
If you are going to carry extra fuel, make sure you have good quality well sealed containers, not just old oil drums.

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Grumpy Old Diesel Owners Club group

I no longer question authority, I annoy authority. More effect, less effort....

1967 230-6 auto parts car. rust bucket.
1980 300D now parts car 800k miles
1984 300D 500k miles
1987 250td 160k miles English import
2001 jeep turbo diesel 130k miles
1998 jeep tdi ~ followed me home. Needs a turbo.
1968 Ford F750 truck. 6-354 diesel conversion.
Other toys ~J.D.,Cat & GM ~ mainly earth moving