Maybe someone can shed some light on this. I just bought my first R* new last month. It is a 2008. It has 286 miles on it and I have gone through 2 1/2 tanks of gas so far. When the fuel low warning light came on last time I decided to check it with my trip meter. I filled it up from empty and I think I remember it took 3 1/2 or almost 4 gallons. I forgot to get a receipt. It is now a little above 1/2 tank and I have only put 48.5 miles on it since fill up. The owners manual says the tank has a capacity of 4.76 Gals and the fuel reserve amount is .9 Gals. It doesn't specify if the capacity of 4.76 includes the fuel reserve or not. Seems like it is getting lousy fuel mileage.

It says in the manual that .9 Gals (Reserve)remain in the tank when the needle reaches "Empty". So I guess the 4.76 capacity includes the reserve. Still seems like it is getting lousy mileage though.

2008 FUEL INJECTED ROAD STAR 1700 FUEL MILEAGE TEST

FUEL MILEAGE DATA ENTRY #1
Documentation starting with 4th tank of gas - Odometer Reading 350
Mileage driven = 111.0.
Fuel added = 3.771 Gals.
Fuel Mileage = 29.435 miles per gallon.
Driving Type = Mixed - Cruising city and highway with many full throttle applications and 2 short high speed runs of 100 and 110 MPH.

FUEL MILEAGE DATA ENTRY #2
5th tank of gas - Odometer Reading 474
Mileage Driven = 123.6
Fuel Added = 3.739 Gals.
Fuel Mileage = 33.056 MPG
Increase of 3.621 MPG since last check.
Driving Type = Mixed city and highway with one short full throttle application to 100 MPH with immediate deceleration.

FUEL MILEAGE DATA ENTRY #3
5.1/2th tank of gas - Odometer Reading 560
Mileage Driven = 86 Miles
Fuel Added = 2.200 Gals.
Fuel Mileage = 39.09 MPG
Increase of 6.034 MPG since last check.
Driving Type = Mostly highway with one short full throttle application to 105 MPH with immediate deceleration.

FUEL MILEAGE DATA ENTRY #4
6th tank of gas - Odometer Reading 678
Mileage Driven = 118.9 Miles
Fuel Added = 3.065 Gals.
Fuel Mileage = 38.792 MPG
Decrease of .298 MPG since last check.
Driving Type = City mixed with highway cruising. No full throttle applications. Probably never went over 80 MPH.

FUEL MILEAGE DATA ENTRY #5
7th tank of gas - Odometer Reading 814
Mileage Driven = 135.6 Miles
Fuel Added = 3.565 Gals.
Fuel Mileage = 38.036 MPG
Decrease of .756 MPG since last check.
Driving Type = Highway cruising with 2 full throttle applications, one of which was up to 115 MPH with immediate deceleration.

FUEL MILEAGE DATA ENTRY #6
10th tank of gas - Odometer Reading 1187
Mileage Driven = 132.7 Miles
Fuel Added = 3.258 Gals.
Fuel Mileage = 40.6998 MPG
Increase of 2.6638 MPG since last check.
Driving Type = Mostly highway cruising at speed limit. Some in town riding.

FUEL MILEAGE DATA ENTRY #7
11th tank of gas - Odometer Reading 1343
Mileage Driven = 155.7 Miles
Fuel Added = 3.822 Gals.
Fuel Mileage = 40.737 MPG
Increase of .038 MPG since last check.
Driving Type = Exclusively highway cruising at 70 to 75 MPH. Only in town riding was to and from the highway.

FUEL MILEAGE DATA ENTRY #8
??th tank of gas - Odometer Reading 2040
Mileage Driven = 146.1 Miles
Fuel Added = 3.478 Gals.
Fuel Mileage = 42.00 MPG
Increase of 1.263 MPG since last check.
Driving Type = Exclusively highway cruising at 65 to 70 MPH. Only in town riding was to and from the highway.

This concludes this fuel mileage road test for the 2008 fuel injected Road Star. It appears the mileage will be around 40 MPG. I hope this can be of use to someone in the future.