Recalibrate sender/trip computer with replacement fuel tank?

[clarkh]

After reading the article on the Transfer Flow 54 Gallon replacement fuel tank, I am wondering two things:



1) does the sender need to be recalibrated for the new tank?

(I'm betting not, since a 1/2 tank indication doesn't care how *much* that actually is!)



2)Can the stock trip computer on my truck be recalibrated so it would accurately display milage? Without doing that it would claim 1. 5x my real milage. The actual amount of 1/2 tank would matter here, and I really like to monitor the readings.



Thanks!

 

[mike65]

Clark , their is no need to recalibrate the sender, on my truck the gauge starts to move off empty after about 140 miles and when the low fuel light comes on it takes about 38 gal. (1/8 tank).

On my next tank i am going to take it down to the Empty line and see how much it takes. The trip computer works except for the distance to empty will stay in the 500 mile range along time before it starts to move down.





Mike

 

[clarkh]

So it sounds like the trip computer does it's calculations based on the fuel delivery system. What does it say for instantaneous and avg mile per galon? ( I'm starting to think the swoopy fuel tank is the way to go!!!)



Thanks!

 

[SLVRBLT]

clarkh-



I have a 90 gal. aux. tank in the bed. The mpg feature, both avg. and instant, on the computer has worked perfectly no matter what tank(s) I am running on. I have checked it against the actual computation and it always agrees. I think you are correct in that it calculates from fuel delivery. My truck is stock, but I have talked to others that tell me once you start the bombing, the computer will not agree with the actual mpg since it is "fooled" by modified fuel quantity delivery.



The distance 'till empty feature uses the position of the fuel gauge and the avg. mpg to compute that figure. (I think I'm right on this). However, it assumes you have 35 gals. (34 for short bed) so that figure will be incorrect. However, once you get used to using a different tank size, it is no big deal.



I think anyone you ask that has increased their fuel capactiy will tell you they like it. I am getting ready to make a trip to northern Minn. , round trip about 2,000 miles, and I will have enough fuel on board to "almost" make it without refueling depending on how much driving we do while there.



Hope this $. 02 helps.



Dave

 

[Wheaties]

My travel computer consistently posts an average mpg about 1 mile per gallon low. You can reset it by pressing both buttons simultanaeously and it will take about thirty miles to get back on track.



I'm wondering if I wait till I'm about to go on a trip to do this, if I won't end up closer to the real mileage.



YMMV,

Matt

 

[SLVRBLT]

Matt-



I always reset the avg. mpg when I get fuel and don't reset it until I stop for fuel again. If you reset it at some distance after you have fueled, you will lose the avg. mpg that has accumulated and the computer will not match the actual.



If I understood your post correctly, this may be the answer to the descrepancy.



Dave

 

[Wheaties]

Dave,



I usually don't reset it at all because it takes so long for it to climb up to a value that's even close. When I do reset it, I do so right after a fill.



It may be that I'm not driving the reccommended thirty miles after a reset. This means the average includes the next engine warm up which would bring the numbers down. One time I did a reset, then got stuck in bumper to bumper traffic.



Have you watched your instantaneous mileage while stuck crawling in traffic? I'm just tickled to death that I can be crabbing along at 5-10 mph and getting 20mpg.



Anyway, I'll have to fill the tank and go drive an hour somewhere to see if that doesn't come closer to actual.



Thanks,

Matt

 

[B.G. Smith]

Computer

I think the computer computes the mpg from the throttle position and the speedometer. The miles till empty are then computed by multiplying the mpg times what is left in the tank. If the trip mileage shows 400 miles and you are getting 20 mpg then you have used 20 gallons of fuel, you should have 15 gallons remaining (35 gal tk) thus 15X20=300 miles till empty.