Moderator: volvite
disallow wrote:At stock size, your speedo reads too slow. So by changing the tire size and gearing, you are probably correcting it.
Check you vehicle speed with GPS to validate, though there is an error factor there as well.
doctahjones wrote:disallow wrote:At stock size, your speedo reads too slow. So by changing the tire size and gearing, you are probably correcting it.
Check you vehicle speed with GPS to validate, though there is an error factor there as well.
in general i would agree with you disallow, but if the speed sensors are between the diff and wheel, changing diff gears shouldn't have an effect on the speedo.
now if the speedo is in the transmission (was i was used to in older cars) then yeah, changing diff/gears for sure will 'level out' the speedo (and reported mpg)
Yep didn't know about the sensor location, that makes total sense.doctahjones wrote:in general i would agree with you disallow, but if the speed sensors are between the diff and wheel, changing diff gears shouldn't have an effect on the speedo.
now if the speedo is in the transmission (was i was used to in older cars) then yeah, changing diff/gears for sure will 'level out' the speedo (and reported mpg)
Mine's the opposite. 75 on the speedo is 71-72 by GPS, which if I'm thinking right means I'm not going as far as the odometer says, so my fuel economy is worse than it is already. And I've only done 15800 miles instead of 16500 and so my warranty will run out sooner than it should!disallow wrote:At stock size, your speedo reads too slow. So by changing the tire size and gearing, you are probably correcting it.
Check you vehicle speed with GPS to validate, though there is an error factor there as well.
Well, in a bit of procrastination-driven googling, it seems that in US an acceptable inaccuracy is up to 5 % (I'm at 4), as long as it is over. Reading slower seems a universal no-no, so manufacturers generally set vehicles up to overestimate a bit. GPS also has its wobbles, but is generally closer to 1%. Of course all that came off the interweb, so who knows...disallow wrote:When I have taken the time to check, there seems to be a directly linear relationship to distance travelled vs how fast the vehicle thinks it is going.
I would have that checked!
t
FLpathFinder wrote:According to the gauge under the speedo, 350 honest!
skinny2 wrote:My gauge and DTE display are pretty accurate as well. The DTE is conservative by a factor of a couple gallons but that's quite normal. My wife's Acura is far more conservative on the miles to empty.
I've been getting in the 19mpg range lately. Today I have 309 miles on this tank and DTE is showing 45 miles to go. I'll fill up when I get back home which will put me at 335 miles and I'll pump 17-18 gallons.
I've gone 40 additional miles AFTER the DTE hit's zero (or **) and still had a gallon in the tank.
So for the sake of argument....what's your actual mpg if you divide miles driven by gallons pumped?
I came here looking to see if this was normaldisallow wrote:For instance, today with DTE showing 29kms and my gas gauge right at the bottom, I filled up. The truck took 64L. It has an 80L tank. But the gauge showed it was right empty. (traveled 430km on that much fuel, which equates to 14.8L/100km or 15.8MPG)