Friday, April 5, 2013

ROG -- Run Out of Gas Testing

The 2013 BMW R1200GS Adventure has a fuel rating of 51 MPG and a OEM stated fuel capacity of 8.7 US gallons.  Hardly anyone riding a BMW R1200GS gets that kind of MPG though.  Check out this cool site that tracks MPG by vehicle type:  Fuelly -- BMW R1200GS AdventureYMMV - Fuel consumption rate is dependent on many variables; sustained speeds, gross weight, wind direction, operating and rider characteristics.  Check out my Fuelly MPG states.

I'm doing some run out of gas testing on the GSA.  The purpose of this ROG testing is to determine the fuel endurance distance (FED) for a tank of fuel under differing ride pace conditions.  I define FED distance as 95% of the ROG distance.  See the testing method below.

Interstate highway 4/5 I-10, Boerne to near I-10/20 merge in west Texas
ROG Point/Stats

  • Speed limit - 80 MPH, moderate crosswinds to quartering headwinds, 70-80F
  • ROG Miles - 351 miles
  • Mvg Avg  - 79 MPH
  • Total gallons at fill up - 9.829 (9.069 + 0.760)
  • Notes - The GSA low fuel light came on at 274 miles.  I rode 41.6 miles past GSA fuel range indicating zero.  Distance from ROG point to Cherry Creek gas fill up was 8.6 miles.  I estimate I used a 0.240 gallon based on 35.7 MPG

US and State highways 4/6, US90 Alpine to Del Rio to Boerne via hill country roads
ROG Point/Stats

  • Speed limit(s) - 70-75 MPH, winds light, 60-70F
  • ROG Miles - 373 miles
  • Mvg Avg - 69 MPH
  • Total gallons at fill up - 9.856 (8.875 + 0.981)
  • Notes - The GSA low fuel light came on at 285 miles.  I rode 46.1 miles past GSA fuel range indicating zero.  Distance from ROG point to gas station was 1.7 miles.  I estimated I used 0.019 gallon based on 38.1 MPG

Secondary roads 4/10-13, Wimberley to Boerne to Wimberley via hill country roads
ROG Point/Stats

  • Speed limit(s) - 35-65 MPH, weather was not an issue.
  • ROG Miles - 421
  • Mvg Avg - 55 MPH
  • Total gallons at fill up - 9.767 (9.571 + .196)
  • Notes - The GSA low fuel light came on at 320 miles on the GPS odometer and the GSA trip computer indicated 42 mile "Range." I rode 57.2 miles after the "Range" indicated zero.  Distance from the ROG point to the gas station was 1.9 miles.  I estimated I used .044 gallon based on 43.1 MPG

100ccc Stats 3/17-21, I-10/12/8 JAX - SDO - JAX (On the clock)

  • Enroute Pit Stops = 13
  • Start/Mid/Finish Stops = 3
  • Fuel Stops at Rest Stops = 3
  • Fuel used Start to Finish =  131.8 gallons (133.393 total minus start fill up of 1.593 gallons)
  • Miles per gallon for event = 35.9 (4,735.1 GPS miles divided by 131.8 gallons)
  • Highest/lowest MPG = 44.4 and 31.7
  • Farthest fuel load distance = 341.1 miles
  • Highest amount pumped = 8.831 gallons
  • Total fuel costs = $533.56 (High $4.40, low $3.69 and average $4.01 per gallon)
Notes  After arriving home from the JAX dinner and 100ccc on Friday 3/22 the GSA indicated 21 miles left till zero on the fuel range counter. Today, 2/28, I fill up a quart sized MSR fuel bottle and got on the motorcycle to run out of gas.  This is my first ROG on the new GSA.  When the GSA Fuel range gauge hit zero I started an odometer on the GPS.  I was riding on I-35 at interstate speeds to burn up what was left in the tank after the ride back from Jacksonville.  By the time the motorcycle experienced complete fuel exhaustion I had traveled another 43.4 miles.  By this time I was doing a turn around via frontage roads off the interstate and pulled into the parking lot of a motel.  I could see an Exxon station less than a 1/4 mile away.  I poured the 0.25 gallons of gas from the MSR fuel bottle and rode to the Exxon.  There I put another 9.584 gallons into the tank.  That's a total of  over 9.8 gallons of fuel.  This is good information.  I will be confirming this with more ROG tests in the next couple of weeks.  I'll do a blog posting to document the results of this fuel endurance distance testing on the new bike.


During these tests the GSA is in near rally trim as far as vehicle weight is concerned.  Tires pressure is at normal rally trim riding pressures of 38 front and 44 rear when cold.  I note the wind direction to take into account effect on the test results.  This is usually not a big effect unless it is strong head or tail winds.

For each ROG category I start with filling the GSA normally, on the side stand, filled to within 2 inches of top of the filler neck.   I put one gallon into an gas container to use at the ROG point.  I'm careful to put just one gallon into the approved container so making the calculation of total gas added at the post ROG fill up more accurate.

Then, I zero the two MC trip meters.  On the zumo 665 I zero out the trip settings; max speed, moving and overall average MPH, odometer, riding and stopped time.  Though, I'm primarily interested in just two of these data points; Moving Avg MPH and Odometer. 

I maintain a normal riding pace for the speed limit and flow of traffic.  The idea is to duplicate my normal operational (on the clock) pace for the type of highway.  When the low fuel indicator/range activates on the GSA I take s screen shot of the GPS to document the odometer/Mvg Avg/fuel countdown data.   When the GSA fuel "Range" number goes to "--------" I zero one of the second GSA trip meter to track how many miles the bike traveled after showing zero "Range".  This also helps me calculate the fuel used from the ROG point to the fill up gas station to more accurately determine total fuel added.  At the ROG point I do a screen shot to document odometer and moving average data.

Applying this method across the different highway configurations helps compare FED among the various riding conditions I will experience doing rallies and the IBR in particular.  The Interstate Highway ROG data is the most significant as it represents the shortest FED I should experience while on the clock.  I will use this FED as my GPS fuel countdown distance.