Several months ago I purchased an RV-6A. The owner claimed 170 mph while sipping gph. I did my homework prior to the purchase and understand those numbers to be common. I love the plane and it does sip 7 gph however the only time I can get 170 mph is i a decent. Typical numbers are closer to 154. Any suggestions for drag points i could look at. The IA on my field is familiar with RV's and feels like the prop ( wood Fixed) is pitched correctly.