I installed 5 star tune and scangague II 300 miles ago on my 2000 Holiday Rambler 35 BPD F53 V10 class A Towing a 2010 Jeep Wrangler. We left FT Lauderdale FL and took route 27 to Ocala FL. I noticed less downshifting on slight up hills, better throttle response, and crisper shifts. According to my scangague II I average 8.3 mpg on this trip. We are taking 5 weeks to get to Santa Cruz CA I will keep reporting on my progress
So for 5 star tune was worth the dollars for 2 reasons customer service and change in downshifting on small grades.