Toyota Tundra Forums banner

1 - 19 of 19 Posts

·
Registered
Joined
·
2 Posts
Discussion Starter #1
I have a 2000 4.7 V8 2x4 Tundra w/140k miles. I took a trip from florida to california and back a couple of months ago and noticed that my gas mileage keeps getting worse. I now get 10MPH. The truck seems to run fine. Does anyone know what could be causing the horrible gas mileage?
 

·
Registered
Joined
·
4,071 Posts
hi, i have talked to the dealership, & every gas station mechanic run into.
i have talked to several mechanic's that i know personaly.
and several motorcycle shop's.
especially the motorcycle shop's-since there gas tanks are small 3gallons to 5gallons. they notice the decrease the most. they all tell me the same thing.
it's the gas!

they have changed the gas.
they know now more than ever, it's because they have added more additive's, besides the winter & summer blend.
therefore that is the reason for all of us getting bad gas mileage.

we all understand the fact, if you always have your foot in it, the mileage goes down.
but even than it shouldn't be what we are getting.

yes, it could be you need a tune up, or throttle body cleaning, or a new air filter.
but what if you did all that, and it's still the same? humm....
again i will say it, i belive the professional's: it's the GAS!

i understand with all my mod's and the way i drive i know i get bad mileage.
when i bought it the sticker said 17mpg city & 18mpg highway. which just don't sit well with me anyway. how could city & highway be that close.


before the unichip i was getting 14mpg, than i added the volant cai, i got 16mpg, wow nice i said.
than the install of the unichip back to 14. but i figured it was o.k. becasue of the hp & TORQUE increase.
than i custom tuned it, and lost another 1mpg, but for another 20rwhp. again i said it's worth it.
350hp & 400 in torque engine not rear wheel.

sorry for the long story, but if you did all these thing's, and if you could do it yourself: oil change & filter, FULL
complete tune up (everything), complete throttle body cleaning 3step kit. injector cleaning, gas cleaning in gas tank, and throttle body cleaning.
and
you still are getting 10mpg, belive me it's the GAS!
at least you have done it all.
and
your good for another 100,000 miles.
regards,
gorilla
 

·
Registered
Joined
·
2 Posts
Discussion Starter #4
Did the air filter and MAF. I did notice it was running hotter then usual the last couple of months. Could timing be the issue?
 

·
Moderator
2015 Toyota Tundra DC SR5 5.7L
Joined
·
8,540 Posts
It doesn't matter whether I'm driving in 32F weather or 102F weather, my 2UZFE has always stayed at the same indicated operating temp. If you are running "hotter" than normal, I would look at a coolant/thermostat issue first. Look for coolant leaks, kinked hoses, and physical damage/debris on the radiator fins.

In regards to your mileage, I would also suggest a good throttle body cleaning as well.

Q: How old and what brand/model spark plugs are you running?
Q: Where do you buy your gas? Do you buy it on the same day of the week?
Q: Have you checked your tires for inflation values and wear? Just a couple of pounds can account for a 2-3% decrease in mileage.
Q: How old are the upstream fuel-air sensors in your truck?
 

·
Premium Member
Joined
·
1,077 Posts
Do you still have the original fuel filter? I would replace that if you already haven't.

Are you running the stock tires? I.E. 265 70 R16 or something larger. larger tires would drop MPG.

Don't bother with a cold air intake.

I 3rd in cleaning the throttle body.

Try this kind of fuel injector cleaner. AMSOIL - P.i. Performance Improver (API)
I have some too if you would rather get it from me.

Send me a PM if interested.
Chris.
 

·
Premium Member
Joined
·
2,875 Posts
In addition to what everybody else has said I'd change the diff to synthetic if you haven't already done so to further reduce friction. Don't carry any unnecessary weight in the truck with you. Gorilla is right about the fuel quality, its the single largest factor in mpg performance. If you're using a particular brand I'd suggest switching to another and monitor your mpgs. I personally chart every tank, keep them in a spreadsheet so I can see any changes plus I keep a log in the truck.
 

·
Registered
Joined
·
122 Posts
Mine is a 2005 regular cab 4WD with the 4.7 V8. The absolute best mileage I have even got is 16. The wife has been driving it to and from work for a while. It is consistent at 11/12 mpg city driving.
I pull a 3500 lb boat most of the time this truck moves out of the driveway. I can count on 9/11 mpg and that's not running it hard either.
I've done everything that can be done to better it. The dealer has had it a few time to see if there is anything wrong and It has always come back as perfect.
I know two guys with 2006 Tundra's. One has an AC, one a DC. Both 4WD V8. Both claim 18/20 mpg. The AC pulls a lawn care trailer every day and he claims 16/17 mpg pulling the trailer in the city.
I don't know....
 

·
Registered
Joined
·
4,071 Posts
hi there are members here that claim 9mpg to 24mpg.
but most of us are between 14 & 17mpg.
but i think 10 is low. even with all my mod's and a full tank for mostly playing hard, i got 13, or high 12's like 12.89
that is doing tap out speed, and running hard off the line.
gorilla
 

·
Registered
Joined
·
115 Posts
My mechanic recommended that I change the fuel filter every 10-12k miles. He said all the junk added to gas these days is bad on mileage.
 

·
Resident Curmudgeon
Joined
·
5,211 Posts
The AC pulls a lawn care trailer every day and he claims 16/17 mpg pulling the trailer in the city.
I don't know....
He's also pulling your leg :D
 

·
Moderator
Joined
·
7,925 Posts
Here is my mileage on my fill up this afternoon. Evenly mixed between city and highway driving. 2004 Double Cab with a four speed automatic transmission (four wheel drive) and I do not drive with a light foot. This is on less than 3 gallons of fuel burned. Oh - and this is with what I consider to be substandard gas from Speedway as opposed to the normal go-go juice from Shell.

Even if we assume 3 gallons of fuel have been burned it comes out to 19+ MPG after you factor in the 1.04 difference for the tire size. (55.2 x 1.04 = 57.4 miles) Going to push into 22+ MPG after the next set of mods.
 

Attachments

·
Premium Member
Joined
·
421 Posts
Here is my mileage on my fill up this afternoon. Evenly mixed between city and highway driving. 2004 Double Cab with a four speed automatic transmission (four wheel drive) and I do not drive with a light foot. This is on less than 3 gallons of fuel burned. Oh - and this is with what I consider to be substandard gas from Speedway as opposed to the normal go-go juice from Shell.

Even if we assume 3 gallons of fuel have been burned it comes out to 19+ MPG after you factor in the 1.04 difference for the tire size. (55.2 x 1.04 = 57.4 miles) Going to push into 22+ MPG after the next set of mods.
OK, Ya lost me on this.

Let me see if I got this right---you logged your mileage when you filled up. Then you drove around a bit, then refilled less than 3 gallons and divided the gallons used by the number of miles traveled and got 19 mpg?
 

·
Moderator
Joined
·
7,925 Posts
OK, Ya lost me on this.

Let me see if I got this right---you logged your mileage when you filled up. Then you drove around a bit, then refilled less than 3 gallons and divided the gallons used by the number of miles traveled and got 19 mpg?
Have not refilled yet - just eyeballed it but believe me I have a real good idea of where I am at on this one. I have a rather obsessive compulsion of watching my fuel gauge.

Tundra Fuel Economy: Watching the needle on my gas gauge

Tundra Fuel Economy: How To Calculate Your Miles Per Gallon
 

·
Premium Member
Joined
·
421 Posts
You have to refill to get an accurate computation, otherwise, just observing the guage is nothing more than a conjecture. Let us know after your fill up what it is.
 

·
Moderator
Joined
·
7,925 Posts
You have to refill to get an accurate computation, otherwise, just observing the guage is nothing more than a conjecture. Let us know after your fill up what it is.
Hey thanks for the observations. I have been doing fuel economy testing for awhile but always welcome advice from any source. By the way, did you get a chance to check out the links I provided or read up on my protocol for fuel economy calculations or experience?
 

·
Premium Member
Joined
·
421 Posts
Hey thanks for the observations. I have been doing fuel economy testing for awhile but always welcome advice from any source. By the way, did you get a chance to check out the links I provided or read up on my protocol for fuel economy calculations or experience?
Yes, I read your reports awhile back. I know you know your stuff, but so many times like your site states, folks claim to get 25mpg because they simply do not know how to figure it out correctly.
 

·
Registered
Joined
·
232 Posts
Hey thanks for the observations. I have been doing fuel economy testing for awhile but always welcome advice from any source. By the way, did you get a chance to check out the links I provided or read up on my protocol for fuel economy calculations or experience?
Unless there is a different section to your website, the last time you posted mpg information was june and july of last year...do you have new numbers for us? I PM'ed and emailed you asking the same question, maybe asking here will render a result that differs from "not a damn thing". Whats new? What are your findings with the fitch fuel catalyst? anything new about the air induction? please, indulge us..
 
1 - 19 of 19 Posts
Top