Gas mileage watch – my 2002 Virago 250 – 17/39 sprockets – Les S.
In the month of July 2011, I went 808 miles, using 8.75 gal, for 92.4 mpg.
In the month of July 2012, I went 896 miles, using 11.07 gal, for 81.0 mpg. (Possible cause of less mpg in 2012: in 2011 bike was more streamlined, I did some hypermiling, tires were 32F/39R, and in 2012 I adjusted the carburetor and tires are much lower pressure than 2011.)
In the month of August 2012 so far, I went 1,053 miles, using 13.08 gal, for 80.5 mpg.
My commute is hiways and two lane roads 45 to 65 mph with some hills. I use premium fuel 93 octane.
Motorcycle Aerodynamics – Streamlining
update 9/12/12 Last week I was getting about 82.8 mpg. I re-installed the passenger seat, and started back using a tail bag – both for better aerodynamics. After doing this plus filling the tires, this week I got 85.7 mpg.
update 9/23/12 I added an enclosure behind the tail bag to improve the streamlining effect. The enclosure (385 cubic inches) can be used for storage. Storage capacity on the bike is now 4,385 cubic inches (2,500 fairing + 1,500 tailbag + 385 rear aero enclosure). I have driven the bike to work once and the tailbag and rear enclosure have definitely made the bike faster. There was one long hill I went up in 5th gear that I had never been able to use 5th before.
A lot of drag is caused by the empty space right behind the driver – adding something to fill in that space (tapered in back) can help. Last year I had a 21 inch (533mm) highaero box and I was getting 94 mpg.
The tailbag/rear enclosure that I have now is 17 inches deep, 14 inches high, 13 inches front width, and 4.25 inches rear width. (432mm D x 356mm H x 330 mm front width x 108 mm rear width)
If you are interested in motorcycle aerodynamics, the Virago 250 is a great bike for aerodynamic mods. Check out the Bob Vetter site and http://ecomodder.com/forum/motorcycles-scooters.html
Today’s Completely Random Fact:
Car 33 mpg, bike1 66 mpg , bike2 33 mpg
In October 2011, I drove 3 different vehicles to work (94 miles round trip). In the same week I got 33.3 mpg with my car, 66.4 mpg with my 1981 Honda CM400, and 99.1 mpg with my Virago 250.
(My wife has always said “no” to me getting a moped – which is too bad, because the next interval would have been 132 mpg.)
Motorcycle tires can lose their air much faster than car tires.
I just checked my tires and they were low (25 psi Front / 9 psi Rear).
For better gas mileage, I normally run 32F/38R.
With a larger rear tire, you can reduce your pressure about 10% – so 32F/38R with a 130 rear tire would be about 32F/34R with a 140 rear tire.
That is one of the benefits of a larger rear tire – you can run a little lower pressure and get a softer ride.
update 8/29/12 I drove the XV250 to work today for the first time since I added air to the tires. It felt like it had about 2 more horsepower – I went up 8 or 10 hills in 5th gear that usually require 4th.
The factory recommended tire pressure is:
Up to 90 KG (198 lbs) load :
25 PSI Front / 29 PSI Rear with 130 rear tire
(approx 25F/ 26R with 140 rear tire)
Over 90 KG (198 lbs) load :
29 PSI Front / 32 PSI Rear with 130 rear tire
(approx 29F/ 29R with 140 rear tire)
9/13/12 – As of today, I have now gone 10,000 miles on my 2002 Virago 250. I have owned it for 18 months.
This is my 10th bike (my others were 160, 350, 400, 450, and 650 cc’s) and it continues to amaze me every day.
Do you wave to people on motorcycles? I do it most of time; sometimes the traffic is too heavy for me to do it. I even wave to people on scooters and mopeds – 8 out of 10 times they do not return the wave as they are not accustomed to being waved to.
To be continued ………….. – Les S.