The quick lube places charge more for a Diesel because they generally hold more oil..... and the oil may (or may not) be slightly more expensive. They still charge way too much though. $87 sounds way high to me, I can get my powerstroke changed at the dealer for $75 and it holds 15 quarts.... of course I can do it for about $25-30. On your car changing the oil shouldn't be too hard..... just get your oil, filter, and something to drain it in (make sure the pan will hold all the old oil). I think there is a cover underneath that you have to remove too but that shouldn't be too hard either. Should save you about $60 a change if you use normal (non-synthetic) Diesel oil.

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1985 300D Turbo ~225k
2000 F350 (Powerstroke) 4X4, SWB, CC, SRW, 6spd ~148k
1999 International 4900, DT466e (250hp/660 ft/lbs), Allison MD3060 ~73k