Ok.... drove the 350 mile round trip to look at both the 8 and 9 today. Both seem to be in very good shape, both crank right up, both have good tires, neither one seem to smoke, but they are definitely not equal in comparison with the way they are equipped. I'm planning on going with the MC-9 afterall. Both have the smooth sided R&M front end and bumpers, but the 9 also has the new style rear cap which makes it look a lot newer than the 8. Also, the 9 has a Turbo'd version 8V71 and the 8's 8V71 does not have a turbo. I could really tell the difference in the two engines. He did tell me that the 9 had larger injectors but wasn't sure what size without pulling the valve cover...maybe 70's or 80's. He did advise me to use that extra power with caution since if it was run hard for any length of time in 95 plus degree weather, that the engine temp would rise and the fuel tank level would lower. He said if it was driven like you had some sense, then the water temp stayed at normal and you wouldn't see much difference on MPG over any other 8V71 with much less power. We drove the bus about 40 miles today and it never got close to running hot. FWIW, the owner has owned both these buses since 1984 and they have only been used for Charter service.
