I have 39k on my '04 TC with Stage 1 burn and White Bros true duals, I keep up on my PM's(periodic maintenance intervals), and have had no problems. Haven't dynoed, but it'll raise an eyebrow on the owner of smaller, lighter models with an A-model 88", and I average about 42mpg in a profile of about 35% moderate city riding vs. a balance of open country roads and interstates at speeds ranging between 55-80mph. I do this with a 5', 100# backseat and all our gear for weekend getaways including heavy items like chaps, jackets, shoes, a laptop computer in a bag and, ultimately, the several hundred dollars worth of merchandise we bring home(some strapped to the rack) every time she(we, lmao) get near an HD store or other road-gear vendors.
I imagine that if I took a longer interstate trip the mileage figure would be higher, but we stick to our region due to work/school constraints and do a fair amount of weekend rides, poker runs, etc. Additionally, I am on the scoot 99% of the time nowadays. It originated with the onset of the highest fuel prices last year and now that they've come down, I feel like i have an opportunity to recoup some gas-bucks(I have a super-clean P-71 Crown Vic with a gasaholic demeanor).
I might add that I sold my Peterbilt earlier this year after 25 years of trucking, and since the beginning of October '08, I've put about 10k on the bike under myriad conditions- hot/cold, wet/dry, high-temp traffic situations- you name it. This bike continues to perform reliably and flawlessly, but I can't over-emphasize the importance of changing fluids and filters and drawing the line where conditions would begin to be considered "extreme" with regard to the big enemy, Heat. Also, it wouldn't hurt to be aware of some service/recall items, specifically the outboard camshaft bearings on the earlier 88's which originated as and inferior application of bearing type, and which has been rectified by a fix that includes roller bearings that withstand radial and axial loading on that end of the shafts much better than the initial design, which was fraught with failures.
If a motor has inherent design issues, there is always a lurking possibility of an unanticipated failure, but we all know that diligent adherence to specific recommended service intervals will, in most cases, yield the performance and longevity we all have come to expect from the MoCo in this generation of motors. I have been very pleased with mine.
Happy Motorin'!
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