Toyota Tundra Forum

I have a 07 RCSB with a 5.7 engine. My truck is a sport package so it has the 4.10 axle ratio and no tow package.
I have 14k miles on the truck and the only mods are a Magnaflow RV muffler and the upper filter removed from the factory aircleaner box.
I felt I was getting better fuel mileage that I expected, way better than the 04 Ram hemi that this truck replaced. Friday morning I had to make a 150 mile trip with several stops and mostly on state highways with little traffic and rolling hills. The outside temp was mid 80s and I filled up with 89 octane Chevron fuel to the top of the filler neck so that you could not put any more fuel in at all. I reset my trip odo and started my trip. Mostly highway driving with little traffic and using the cruise control set at either 60 or 65 mph. I noticed that I had driven over 70 miles before the fuel guage even moved down to the full mark and when I got back to the starting point with exactly 150 miles on the odo the fuel guage was halfway between the full and 3/4 full mark so I knew it would not take much fuel to refill the tank. Using the same station and pump I refilled the tank to the same point where it would hold no more fuel and I was looking at fuel standing in the filler neck that could not go down so I knew the tank was full and could not hold any more. The pump read 5.54 gallons. I could not get another drop in the tank. DO THE MATH! I get 27.075 mpg! Bear in mind the engine rpm was running at or below 1500 rpm all the way. A/C was ON.
I found this hard to believe but I know the facts and there can be no mistake. I do run Mobile 1 full synthetic oil for what good that might do. I do have a hard bed cover also.
Tuesday morning I will make a 50 mile trip mostly highway and I will try this again.
Has anyone gotten even close to this mileage in a Tundra even if you have a V6 much less a 5.7 V8?

I've gotten over 25mpg with a good tail wind in my RCLB 5.7 over a whole tank of gas, and have had many trips over 400 miles over 22mpg with less than flat terrain. Even now at just over 22k, with a full topper and a permanent rack, I still get 20mpg regularly on the highway but about 10-12 lead footing it in town.

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5.7L RC Longbox, 4X4 SR5

If I don't have to idle too much in town traffic I get around 15 per tankful. Just proves these powerful trucks can get decent fuel economy if driven conservatively. It is just too tempting to want to feel all that power on tap!

I drive this 2007 Toyota Tundra Dlb Cab Ltd. Its top speed is 118 mph. The tire size is 275 55R 20 on the limited edition. I use Hankook Ventus ST RH06 tires on this truck to add traction and excellent road handling. It does get 20 to 24 mpg using Chevron 89 or 91 octane fuel. Keep it clean with BG44K in the gas tank. It has 68K miles on it as of September 2008. I know alot about this truck. Keep the cruise control on and the RPM's down, even at 75 mph can achieve awesome gas savings.Ask me a question and I can tell you the answer.

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Filling the tank that high is BAD. There is a carbon filter in there that cleans any vapors that leave the tank. If that filter is full of gas, the filter goes bad quickly and is expensive to replace.

Anyway, nice average. Wish I got that high but my truck can't go that slow outside the city.

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2007 SR5 Crewmax 5.7L 4x4
Mods: nerf bars, Truxedo tonneau, radar detector power, 3M clear bra, fog lights, black billet grille, rear differential breather, parking sensors, Line-X, power tailgate lock, hood safety latch mod, one off driving lights behind grille, Pioneer NAV w/ OEM camera, Flowmaster 50 SUV dual/dual, blue LED dash lights, Volant CAI, Llumar tint, CompuStar Pro alarm, ProComp 6066 20" wheels, Cooper Zeon LTZ 275/60/20 tires, OME HD coilover lift, Firestone helper air bags, stereo cable lock, Tekonsha P3 brake controller
All mod descriptions and pictures © 2007-2009 by Toxarch. They may be copied only for personal use and the mods may be done for non-profit only.

I only fill up that far when I am going on the highway immediately and use up the fuel soon. I never fill up like that and park the truck. It is the only way I know to get a accurate mpg test. Fuel guages are too approximate in their readings.
I have now gone 90 miles in town and the guage is just barely above 3/4 tank. Probably would take about 5 gallons to fill it back up but that would be around 18 mpg. I drive conservatively unless a mustang gt tries to pass and I just don't let them! I could not be more pleased with my truck. If I buy a car I wonder how a new V6 Camry runs?

It doesn't matter how fast you burn the fuel to lower the level. It's activated charcoal that has kind of pores all around the surface. It catches particles in those pores to clean the air. It can only catch so much until those pores are full and the charcoal is no good anymore. If it's surrounded by gasoline, then those pores fill quickly and the charcoal is no good anymore and has to be replaced. If it only gets fumes around it, then it can work for a long time.

Um, I have always filled mine to the brim, LOL.
How much Mula are we talking about?
Do you have a part number?

This might explain some recent hesitation I've noticed...

You'll get a check engine light when it goes out. I don't have a part number or a price. I did a quick search and here is a report from someone with an 08 Highlander who had to have the canister replaced after 2.5 months of over filling. Cost him $1700 at the dealer.

IN RE: Toyota 2008 Highlander Hybrid Gas Tank Damage. - Toyota Forums :: Toyota Nation

Thanks Tox!
No more overfilling for me.
From the article you found, its good advice for any late model vehicle.

Thanks Again