My 2007 Tundra seems to have a pessimistic fuel gage.
When the gage reads a little past 1/4 there is still at
least 1/2 of a tank.
I wonder if thats on purpose...On page 373 of the users manual, it talks about possible damage to the catalytic converters if the vehicle is ran with an extremely low fuel tank. Just a thought!
I wonder if thats on purpose...On page 373 of the users manual, it talks about possible damage to the catalytic converters if the vehicle is ran with an extremely low fuel tank. Just a thought!
Why would it damage the catalytic converterters to run the tank low. I can see a fuel pump of pluging a fuel filter but the cats .
My truck does the same thing. I am sitting at just under 1/4 gonna try to run it low this time. I have yet to put over 20 gal in the tank.
When I filled up right when the gas light came on, it took 20 gallons. I drove until the computer said "0 miles to empty" and actually a few miles more and it still only took a little over 21 gallons. I didn't have any problems with fuel pickup at those fuel levels even at full throttle.
I noticed this as well. When the gas light came on in my Dodge Quad Cab it meant that there was only 8% gas left.
What ever happened to E meaning empty???
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07 Toyota Tundra Limited DC
4x4, 5.7L, Red Rock Leather
Cold Weather Package, Remote Start,
20" wheels, DVD NAV w/Bluetooth, Rear DVD w/10" screen, Formula 1 Tint, Access Tonneau Cover, TRD Dual Exhaust, WeatherTech Floormats
most people on some other forums, including myself are only getting 20 or a tiny bit over 20 gallons in after driving a while after the light comes on, i noticed on my tacoma also that the gauge moved fast throught the first half and slower through the second, probably has a lot to do with the shape of the tank and position of the sensor/pump assembly. supposed to be a 26 gallon tank so that means you ahve 6 more gallons after the light comes on which translates to about 60-80 miles.. but im not go to drive it till it dies to find out.
I wonder if thats on purpose...On page 373 of the users manual, it talks about possible damage to the catalytic converters if the vehicle is ran with an extremely low fuel tank. Just a thought!
Because when you run your tank very low, the fuel pump maybe unable to pick up fuel which causes fuel pressure dropouts. That causes the fuel mixture to run lean which then causes the exhaust temps to skyrocket. The higher than normal exhaust heat will kill your cats. As it is, most manufacturers set their mixture to rich when you go wide open throttle, this not only improves overall power but also keeps the exhaust temps cooler. The EPA doesn't test at WOT so the mfr's could care less of all the extra HC going out the exhaust pipe.
I still think you're more likely to cause damage to your pump than you are to the cats. The cats have to be warrantied for 10 years so maybe they're being extra careful but I'm sure the manufacturer would love to sell you a new pump.
Because when you run your tank very low, the fuel pump maybe unable to pick up fuel which causes fuel pressure dropouts. That causes the fuel mixture to run lean which then causes the exhaust temps to skyrocket. The higher than normal exhaust heat will kill your cats. As it is, most manufacturers set their mixture to rich when you go wide open throttle, this not only improves overall power but also keeps the exhaust temps cooler. The EPA doesn't test at WOT so the mfr's could care less of all the extra HC going out the exhaust pipe.
I still think you're more likely to cause damage to your pump than you are to the cats. The cats have to be warrantied for 10 years so maybe they're being extra careful but I'm sure the manufacturer would love to sell you a new pump.
I could see this happening in an older vehicle but not a brand new one where virtually all aspects of the combustion process are controlled by a computer. Although I do not know for sure, I'd have to think that low fuel pressure would throw a code and at the very least change the ECU's fuel maps to compensate for less fuel. But then again, if it did, why would the manual warn otherwise.
As far as dumping in more fuel at WOT, this is generally true in newer vehicles for that very reason, killing the cats with too hot EGT's. However, in most cases, this robs the engine of power if the mixture of air-to-fuel is too rich (which it generally is for safety). A safe leaner mix (say 12-13:1 air-fuel ratio) is ideal and I think you'll find that alot of vehicles today tend to approach the 10:1 mark at WOT near redline, fairly fuel rich. I leaned out my 4Runner to 13:1 (down from 10.5:1) at redline and saw significant peak power increases as well as better throttle response and more torque at lower rpms from tuning the air-fuel ratio.
On my 5.7 L I too have seen the "pessimistic" fuel gauge. I have filled the tank twice and it was never really came close to being actually empty. I am getting 15 mpg per the computer in driving that is 2/3 around town driving with hills and 1/3 flat freeway. I am pretty pleased with that.
Just for fun I ran mine till the light was on and the computer read 0 miles left. I then drove another 20 miles before filling up. I put 22 gallons in. I could have gone another 50 or so miles. Diffirent from what I am use to but once I get it figgured out it will all be good.
Tundra 07 fuel gauge
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Linear Mode
