Fuel Economy

Since I always fill to a full tank it’s easy to monitor mpg. The data below is based on the amount required to fill the tank and the associated odometer reading. It covers every fill up since new. It does not reflect the instant/average consumption provided by the ECU.

I don’t ride to get the best milage, but am certainly not the fastest rider either. Most of the riding is through local mountains, but with some freeway (getting to/from the mountains) and occasional commuting, usually through packed streets (involves a lot of lane splitting and waiting at red lights)

Some observations: the average mpg (as shown by the black dashed polynomial trend line) improved between 1500 and 8000 miles, possibly as the engine loosened and riding style/habits adjusted to the bike - the difference is not however very significant. The trendline suggests the economy has been decreasing (very slightly) since ~8000 miles. I changed the air filter (which was very dirty) at 9925 miles, but there is no evidence that has changed consumption in any way. One possible explanation for the decline (aside of needing a service) is the Pilot Powers that went on at 9500 miles, and I know have encouraged a slightly more aggressive ride in the canyons.

Another observation is that changing the 19 tooth front sprocket to an 18 tooth (at 4661 miles) and installing the off-road exhaust/tune (5226 miles) did not appear to affect milage. One caveat though would be that this data is all based on the odometer reading, which will be under-reading by approximately 5% since the 18T sprocket was fitted


Gallons (US)
























Tyre Pressures

Although the manual recommends 36 psi for the front, and 42 psi for the rear many riders consider these too high. As with everything related to engineering, it’s about compromise. Since motorcycle tyres depend on being warm for optimum grip, it’s desirable to have the pressure such that sufficient carcass flexing occurs to warm the tread. However, too much flexing will not only compromise ride quality, but also possibly lead to overheating of the tyre, which will at least lead to reduced service life but could lead to catastrophic failure.

The ideal way of setting the optimum tire pressure is to measure the temperature immediately following a ride, and adjusting the pressure for each ride to converge on the optimum temperature as defined by the tyre manufacturer.

In the absence of a suitable temperature measuring device and possibly the manufacturers temperature data, there is another method based on change of tyre pressure. Since air expands when heated, tyre pressure increases (the volume can’t change, so the pressure exerted by the more active air molecules shows as increased tyre pressure) - at least that’s the theory. A common rule of thumb is to seek a 10% increase in front tyre pressure when comparing hot with cold, and 10 to 20% increase in the rear. It is based on these estimates that I have collected some limited data (19 readings) since mounting the Pilot Powers.

Understanding the charts: Let’s take an example. Look at the front tyre chart with a cold pressure of 33 PSI, on the x axis. In this case the range of readings (there happens to be 4 data points) is from 35 to 37.2 PSI or 6.4% to 12.7% - the limits of the blue vertical bar above the 33 PSI. The mean of the 4 measures equates to 10% - the black horizontal tick and associated red trend line.

Conclusions: The red trend line suggests that for my weight and typical riding style that a front cold pressure of 33 psi (rather than the recommend 36 psi) yields the optimum warm up and hence grip. However, the data also shows there is a significant variance in warm readings. This no doubt is a consequence of ride distance, type, ambient temperature and bike loading. It can be observed though that running at the recommended pressures does not for me create sufficient flex to warm the tires to optimum grip. This agrees with my subjective feeling of the bike, and the findings of others.

Disclaimer: given the wide number of variables your results will vary. I share this in the hope it will encourage others to take a similar approach to optimising their ride, but like suspension tuning everyone needs to configure for their circumstances.



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