18 or 21?

I have a question about 07' Tacoma gas gauges. Is yours calibrated to show 18 gallons (18 gal + 3 gallons reserve), or 21 gallons. In other words, when you use a half-tank according to the gauge, have you used 9 gallons or 10.5?

According to my scangauge II, mine is calibrated to only show 18 gallons (3 gallon reserve tank). Also, is there any way to change the gauge to show the full 21 gallons?

Thanks,

Ted

 

No one knows, huh? ok.

 

The tank holds 21 gallons. The gas light comes on at 3 gallons left. You can adjust the scangauge to the size of your gas tank. Read the manual.

 

Yes, i understand that i can adjust the scangauge, I did that when I first installed it. Im talking about recalibrating the factory gauge.

Ted

 

when i use half a tank and fill it up max where u can see the gas almost overflowing out of the tank i use anywheres from 12-14 gallons. i dont know if that helps yah or not...

 

i think i know what you are talking about. i have a 2007 tacoma, and i have come pretty close to running out of gas, i know the owners manual says 21 gallons. but i am not to sure because i have had my gauge all the way down to red, and when i fill up it fills up about 17. something, never 21. so whats up with that. if i go all the way to empty what is suppose to happen. maybe i should run a test, just drive until i run out of gas or something. let me know if you all find anything out.

 

Why would you want to recalibrate? When the needle gets to the red then you have 3 gallons left, which means you can now fill it up with 18 gallons of gas.

I don't understand what you want.

 

Thats exactly what im talking about, Manofs

 

First off, the tank gauges on almost all cars are not very accurate. Since they are based on a float in a tank, they have quite a bit of room for error (up to 2-3 gallons in some vehicles!!!) Just because it says you have half a tank, doesn't necesarily mean that's where you're at.

The only accurate way to know what is in your tank, is to know how much is in there (21 gallons at full tank), and measure how much you take out (usually measured by the ECU for injection metering).

I have not gone this far, but theoretically you could get the numbers from the ECU and calculate how much is left in your tank by how much you have used. There are some people on http://tdiclub.com that have done this, but I am too lazy to go look for the posts.

I get mine down to half a tank, fill up, and only get 8-9 gallons in. When I drain it "dry" (according to the gauge), I fill up with about 17.5-18 gallons.

It doesn't bother me. I rarely let my tank run that dry.

 

ok, so why would the owners manual say 21 gallons, because it the tank only hold 18 some odd gallons then when i calculate my gas mileage should i only calculate for an 18 gallon tank, or 21.....?? but i do understand what you are saying...

 

No, the tank is actually 21 gallons.

The gauge only shows ~18-19 gallons worth.

I can only guess that this is to help prevent people from running out of fuel by "pushing their luck". The newer fuel injection engines are not forgiving of running out of fuel like the old carbs are. You can cause significant damage by running a modern FI engine out of fuel and trying to prime it back up by cranking it.

 

hey thanks 007, good info to know. so if i were to hook up a scangage II, it would be best to calibrate it for 21 gallons, so i can get an accurate reading to when i am actually going to run of gas????

 

I am not sure of the features of the Scan Gauge II, and I don't want to lead you wrong.

 

Yes. You need to calibrate the scangauge II for 21 gallons. This is how i figured out the OEM gauge was screwy in the first place.

 

Ive ran my toyota to almost empty. the gage was below the empty line and i filled up completely as in the gas was almost over flowing.. and it read 20.46 or so galons.. so i think the 21 gal is the taco topped off.. hope that helps and maybe you guys could try it and see if you agree?