Jump to content
CBR1100XX.org Forum

GPS vs Odometer?


Zero Knievel

Recommended Posts

The Garmin Zumo 660 has a "gas gauge" feature where if you set the miles until empty, it will give you an alert as to when you're getting low.

 

What I noticed, however, is that it was about 30 miles off...saying I have gone about 200 miles (what I set) and the trip odometer was saying 170ish.

 

I'm running a SpeedoHealer, but I'd think that should correct a discrepancy, not cause one.

Link to comment
Share on other sites

Your speedo healer may alter the speedometer "how fast am I going" pointer, but it also alters the odometer reading.  While an XX speedometer is quite optimistic, the odometer is pretty much correct.  So making the speedometer read the correct speed (slower than it wants to read) makes your odometer record less mileage...so you run out of gas sooner, or so it appears.

Link to comment
Share on other sites

3 hours ago, rockmeupto125 said:

So making the speedometer read the correct speed (slower than it wants to read) makes your odometer record less mileage.

Surprised that is legal to sell.  Kind of like spinning the miles back with a drill in the old days.

Link to comment
Share on other sites

I just go by the odometer and fuel gauge. Once you get a baseline established in your memory, you don't need the extra thought or gadgets. I know this... the first half tank goes a lot longer than the second :)  When I'm riding the bike off interstate, i mentally calibrate the difference. I recall a recent trip that i was being VERY mindful of fuel consumption. Turns out, I made it to the station without a clue the miles i had trekked, just using the red blinking (oh shit ima b walkin') light.

Edited by Hooplehead
  • Upvote 1
Link to comment
Share on other sites

Yep what hobblehead said. 

 

Normally I get 90 -100 miles till I loose the first box... then its click click click down. normally with e10 i get 180 - 190 miles per tank. 

 

on a trip north last year I got low 50's mpg when I did the math, forget exactly was either 51 or 52. Buddy was pissed as his honda accord gets better mileage than his C90 zuki

Link to comment
Share on other sites

4 hours ago, The Krypt Keeper said:

. Buddy was pissed as his honda accord gets better mileage than his C90 zuki

That is something I have never understood 

Link to comment
Share on other sites

18 hours ago, rockmeupto125 said:

Your speedo healer may alter the speedometer "how fast am I going" pointer, but it also alters the odometer reading.  While an XX speedometer is quite optimistic, the odometer is pretty much correct.  So making the speedometer read the correct speed (slower than it wants to read) makes your odometer record less mileage...so you run out of gas sooner, or so it appears.

 

Well, that's the deal.  I have set gas stops based on miles.  With the SpeedoHealer, it's always seemed spot on for the gas stops.  Keep in mind, if my GPS is saying I went 200 miles and my trip odo says I've done 175 and I still get to 200 before needing gas, what does that mean?

Link to comment
Share on other sites

6 hours ago, Aunt Sylvia said:

what does that mean?

That this post is by you.  You have an odometer & fuel gauge on the dash and you already know your bike's range....so WTfuckingF?!?

Link to comment
Share on other sites

What I mean is that if my trip odometer hits 200 before I need gas and the GPS is saying I hit 200 miles 30 miles ago...what's my actual range?

 

I'm going to have to clock distance to see if the trip odo is off.  It never seemed to be before.

 

Not that GPS-measured mileage is foolproof.

Link to comment
Share on other sites

I would do the simple math on my fingers or in my head. 

 

The GPS gives an estimate at best.. I wouldn't trust it for fuel when I have to use common sense using it to map out stuff. 

 

Unless I want to go down goat paths in a car or turn into fields for quickest routes and other crap they are known for.. 

 

As mentioned you have a gauge and odo.. Run multiple tanks as a baseline and average.. Its not rocket science.. 

 

 

Link to comment
Share on other sites

13 hours ago, OMG said:

That is something I have never understood 

Well the c90 is what 1500 or something cc's twin and believe 5speed gear box.. 

 

Big cylinders to feed, and no real power to justify a 6th gear for highway. 

 

Maybe I am wrong, but his bike is bone stock and would hate to see what it would get with some tweaking to exhaust and fuel management system or jets.. Don't know what it is. 

Link to comment
Share on other sites

9 hours ago, The Krypt Keeper said:

Well the c90 is what 1500 or something cc's twin and believe 5speed gear box.. 

 

Big cylinders to feed, and no real power to justify a 6th gear for highway. 

 

Maybe I am wrong, but his bike is bone stock and would hate to see what it would get with some tweaking to exhaust and fuel management system or jets.. Don't know what it is. 

Well yes but generally speaking a bike gets relatively poor fuel milage. Much less weight, much smaller tire patch, arguably less width and height so less resistance, smaller engines and still not a huge difference in milage.

IE: My Audi A8, full size 300 hp, not sure about weight but I can't pick it up if it falls over, gets 23 - 24 mpg. The bird, 45-46 so twice the milage but it's not half weight of the car.

Half the hp yes.

Link to comment
Share on other sites

Air drag on most bikes is pretty high for their size, rider position makes a big difference on most bikes.  The engine and gearing is generally set up for performance, most bike engines just aren't very fuel efficient.  Engine design makes a huge impact on fuel economy regardless its HP potential, all engines are built with a bunch of compromises, some come together better than others.  A car can roll down the highway at under 2kRPM, while the bike is at 4k+, more losses in the engine and trans.  Around town the bike has the edge being light, cruising the highway aerodynamics matter and weight means nearly nothing.  I'll bet Dave's hot rod Vette gets better highway mileage than many normal cars, high gears and low air drag.  Then there's the driver variable.  Even tho I drive more aggressively than anyone I know I generally get better mileage than they do in the same cars under most circumstances.  Open highway cruising some might win since I drive faster, but my maintaining a constant speed helps compensate over most drivers.  The best mileage my Explorer ever got was towing my jet boat to Az.  An extra 2k+ pounds and 4 more tires on the ground, but I drove slower which makes a big difference with an unaerodynamic vehicle.  The boat being low and narrow presented little drag, the engine sticking up in the back was probably the biggest air drag and that aint much.

 

My stock little cherokee with a 160hp 6 cylinder gets less highway MPG than my friend's bigger and heavier lifted grand cherokee with 35" mud tires and a 300hp V-8.  Why?!?  The body on his is more aerodynamic and I'm sure his engine is more efficient, especially since mine needs about 1/2 throttle to propel the brick through the air at 80+mph.  Mine might do better around town being that it's much lighter, but engine efficiency is still on his side.  I think the worst I've ever had was '80 F-250 with a 351M, that engine had no power and got shit mileage.  Ford packed the shittiest combination of things into that motor; compression ratio, bore/stoke ratio, rod/stroke ratio, cylinder head design, cam timing/profile...  Lots of it was great stuff for high RPM use, but the cam profile & compression didn't let it do anything above 4kRPM so it was just a shitty motor.   My bigger heavier lifted 300+HP F-350 with 37" mudders seems to use less gas; I haven't calculated it, the numbers might make me stop driving it.

Link to comment
Share on other sites

Join the conversation

You can post now and register later. If you have an account, sign in now to post with your account.

Guest
Reply to this topic...

×   Pasted as rich text.   Paste as plain text instead

  Only 75 emoji are allowed.

×   Your link has been automatically embedded.   Display as a link instead

×   Your previous content has been restored.   Clear editor

×   You cannot paste images directly. Upload or insert images from URL.

×
×
  • Create New...

Important Information

Terms of Use