2020 F3 Ltd Fuel Economy

[McRuss]

The fact that your odometer/trip meter isn't EXACTLY accurate shouldn't be a real issue, cos that inaccuracy won't vary much at all over time, so your 'measured miles travelled' will almost always be directly comparable to any other 'measured miles travelled' that you've recorded from the same odo/trip meter.... unless maybe you've fitted new tires recently?? Cos that will vary the 'miles measured', albeit usually only a tiny amount if you stick with the same brand/type/size of tires, but possibly as much as maybe a few percent if you've changed tire brands &/or sizes.... Still, since your Odometer/trip meter is pretty much ALWAYS going to be consistent in its inaccuracies, and it's NEVER going to be EXACTLY accurate anyway, you might as well just use the trip meter reading to record your 'distance travelled or measured miles travelled' & simply work off that - trying to get your 'measured miles travelled' any more accurate will rapidly see you spiralling down a rabbit hole chasing after an always elusive & never truly achievable exactitude!! :gaah: Altho if you are riding in an area with good satellite reception all the time & you have a proper GPS with multi-satellite reception capabilities that stays on all the time rather than a 'street directory' type GPS, then you could use the distance travelled between fuel stops that it records?! Maybe...

Regardless, in most cases, those 'dash computer generated' instantaneous MPG readings are even more inaccurate & pretty much always significantly more inconsistent than working out your average miles per gallon over 5 or more tanks of gas using however much fuel you've used over however many miles (even if you've manually calculated that mpg using 'known to be inaccurate distances due to speedo/odo inaccuracies' and the inaccuracies that are found between different gas pumps figures!) simply because the computer will be working off those same 'inaccurate' distance travelled figures anyway, PLUS they'll also be using the most recent instantaneous fuel use readings supplied by your injector system!! There is some 'averaging' of that which varies between make/models of vehicle &/or computer, but it's always weighted heavily towards the most recent fuel flows based upon your most recent driving, so if you back off on the throttle as you gently coast to a stop you'll usually see a better MPG reading than if you've just been working the engine & blasting thru the twisties high up in the rev range & you then just pull up & instantly shut down!! Of course, the better the software & the greater the computer control, the better that computer generated MPG reading can be, but it will ALWAYS be biased towards your most recent riding, so it's not necessarily all that great an MPG reading to go by when working out something like a 'safe ryding range between fuel stops', cos it's nowhere near a 'long term average' and if you rely on achieving that sort of milage over a full tank under different riding conditions, you might well end up walking!! :lecturef_smilie:

Same thing applies to working out your fuel economy on just ONE tank of gas & relying on that for your 'safe ryding range between fuel stops' - it might not be quite so 'instantaneously biased', but it's still going to be a figure worked out over your most recent riding - so if it looks really good cos you've just done a couple of hundred miles riding lightly loaded with the wind behind you on the open highway travelling at 50 mph, then relying on achieving that same MPG to work out your expected range while riding into the wind with a full load & your pillion passenger aboard as you blast thru some high speed twisties at or close to peak revs all the time is probably gonna see you walking well before you ever expected to run outta gas!! :gaah:

To give yourself a reliable & helpful 'average fuel economy' figure, you need to keep a record of how much gas goes in at every fill-up, how many miles you've travelled on that much gas, and you need to use at least a few tanks-full to arrive at a meaningful & useful average. Do that religiously and keep refining the average as you go, and your 'average fuel economy' figure will get better and better over time! hyea: Sure, it'll vary up & down a little as your ryding style, conditions, & loads change for each ride, but the more tanks of gas & miles covered that you use, the 'more accurate' it gets - but be warned, it still might not cover you for those odd infrequent occasions when the roads/conditions are so much fun (or tough), your load is so high, or you ride so hard that your machine is working at it's absolute limits all the time; and on the other end of the scale, you might occasionally get absobloodylutely phenomenal range because everything worked together to make saaay, 500 miles on a tank of gas possible just this once! :shocked:

Oh, OK.

 

[AeroPilot]

Isn't fuel mpg better in the high country than compared to flat lands?

As a former science teacher I decided to test the hypothesis that “you get better gas mileage at higher altitude”. Yesterday three Spyders took a little ride from Pueblo up to Cripple Creek, 160 miles roundtrip and starting at 5000 ft up to 9500 ft elevation.

The route was about half the miles (76) on highway 50 at a speed of 62 mph, and the remainder varied from 30 to 55 up highway 9 and then High Park road. The total one-way time for 80 miles was 1.6 hours and an average trip speed of 50 mph.

This morning I fueled up at the same Shell station and pump with premium, and did the standard automatic fill, and then one more click to fuel up with 4.21 gallons. The total odometer reading of 163 miles and I come up with 38.7 mpg for the trip. As I was down to 2 bars on the gauge it matched many other fillups, but did not meet my expectations of greater gas mileage at higher elevation, especially as my average speed for the route was 50 mph---- I would have expected 40 mpg plus at that speed, as I often get 200 miles per tank and 40 mpg running across eastern CO and Kansas at 60 mph plus.

I can only explain that the lower gas mileage was due to the up and down terrain and while I rode sedately at the speed limit, the curves and hills did require some up and down shifting between 5th and 6th on the SE6 (sometimes 4th). Since our Spyders all have MAP sensor fuel injection I would think the overall efficiency would stay the same regardless of altitude.

I guess a better test ( and many duplicate tests) would be to find a relatively flat course at sea – level, versus a relatively flat course somewhere in the Great Basin (about 6000 ft elev.) where you might run unobstructed for a hundred miles or so. Any takers? Oh well, its fun to check the data occasionally and one run does certainly not prove or disprove a hypothesis.

Now lets see-- what was the original question?:roflblack:

 

[McRuss]

As a former resident of Colorado (Durango, Gunnison and Denver) and a transplant to Texas, leaving behind kinfolk in both Durango and Denver, I had many opportunities to visit Colorado on both of my Yahmaha FJR1300's. I always got better mileage in the high country of Colorado than in Texas, riding pretty much the same in both places. Up until recently I was very careful to log each and every tank and calculate the MPG's. So I went back to my 2018 spread sheet and here is what I found:

Between March 6 and May 31, 2018, I averaged 43.28 mpg over 10 tanks with four under 45 with highest 47.03. All in Texas
Between June 28 and July 23, 2018, I averaged 46.24 mpg over 13 tanks with two under 45 and five over 50 with highest 56.54. All in either New Mexico or Colorado.

So in my mind, and backed up with my records, I got better mileage at higher elevations. And that with a fuel injected motor that should have adjusted for altitude. Since I was on a 'trip', I suspect I drove faster in NM and CO than in Texas though I did have to cross West Texas to get to either of them!