Slowly working toward that magical 20 MPG

[Highwaylizard]

Okay, still have a few more tricks up my sleeve but this is just the beginning. Take into consideration that at 75 MPH I am actually doing 78 MPH. I will be installing the true speed when I get the time - hopefully this weekend. I also have the passenger side manifold O2 sensor out to lunch and need to replace that this weekend too.

At any rate, 78 MPH divided by 75 MPH yields 1.04. I ran until the tank was dead nuts half way and looked at the odometer and she read 233.7. So:

• 233.7 x 1.04 = 243.048.
• 243/12 = 20.254.

Let's just call it 20 MPG. Two pictures below. First picture shows the speed at which I ran and the tank just a hair over half full. Second picture shows the RPM's along with the cruise control set and the CEL for the failed O2 sensor. I would have snapped a picture of the tank at dead nuts half full but by that time I was navigating the turns onto 465 and through traffic.

All this in a four speed automatic, four wheel drive, Double Cab. The new ram air intake scoop is finished and the mounting bracket will be fabricated this week as well. I expect the performance numbers to improve slightly but nothing major beyond what I currently have. The next two modifications (Headers/y-pipe and electric fans) should place me squarely at 22 MPG. The last modification will be another of my own design and I hope to push into 25 MPG on the highway.

[highlevel]

That is pretty amazing. Was the truck completely empty? I just got a Scangauge II and could get better mileage if I lived on flat land. I was recently driving on a level road and was getting 22 - 24 mpg by keeping my foot light. The starts and uphills are where I lose everything. I live in the mountains and constantly haul 800 lbs. plus.

What headers and fans are you looking at. I was contemplating doing the electric fan conversion myself. Also read about changing out the... brain fade... underdrive pulley?

[2000tundra2wd]

i've had mine go over 200 miles at half tank twice.

[JBK23]

Seem like the little green shifter light has gone out on your truck !

[2000tundra2wd]

so is 75 the speed you see the best MPG? it seems that most people on here get the best at 58-65

[Stan412]

I am looking forward to your electric fan conversion. Which one are you leaning toward? I want to do this mod as well and am looking at the Flexalite 775 made for our Tundras.

[ianfromdaygo]

if im driving on the freeway only
long trips 60-65 mph
my truck will get 250-260 on half tank
the best ive gotten so far is 22mpg
driving from stockton down to san diego

[Highwaylizard]

Originally Posted by highlevel

That is pretty amazing. Was the truck completely empty? I just got a Scangauge II and could get better mileage if I lived on flat land. I was recently driving on a level road and was getting 22 - 24 mpg by keeping my foot light. The starts and uphills are where I lose everything. I live in the mountains and constantly haul 800 lbs. plus.

What headers and fans are you looking at. I was contemplating doing the electric fan conversion myself. Also read about changing out the... brain fade... underdrive pulley?

Hey Rob,

Thanks for the kudos - it has been an interesting trial and error process for me; sometimes at rather embarrassing expense. On the trip down to the river we had 100 pounds of electrical cable to try and repair a drop that accidentally got cut by a zero turn mower. Probably not a good thing for people to drink and then mow the grass but I digress. We stopped three times on the way down for bathroom breaks and got lost on the river and ended up tooling around Madison and then Veevay until we found our road. It was the first run to the river for me. Just me and my son in the truck as far as passengers.

The first part of the trip was mostly flat but down at the river it was pretty hilly until we got to our location. No major hills but certainly nowhere close to flat either. Both directions out and back were in constant, sometimes heavy, rains.

Unfortunately Boost Brothers do not produce a header for my year truck - if they did then that is what I would shoot for. As it stands I will probably go with JBA which is a sizable chunk of change and will have to wait until I get some other bills taken care of first. I am still trying to get the money together to pay for my front differential.

I am looking at the perma cool electric fans as well as the Flexalite but have not made any decisions in that area yet. I still have some time to research that modification before the end of he summer.

I would love to get a Scanguage but there are always pressing bills to be paid and I am bucking hard to get the truck paid off this year so I can go to college. Maybe I could convince Boost Brothers to make a set of 2004 Tundra headers and have them donate them to me for testing. I could post up all the results on my Blog. Sponsorship would be a very good thing. - maybe one day. Then again, monkeys may fly out of my @$$ holding $100 bills shouting hallelujah.

22- 24 MPG with DC is phenomenal!! Now I feel totally inadequate.

[Highwaylizard]

Originally Posted by 2000tundra2wd

i've had mine go over 200 miles at half tank twice.

Time permitting I would be happy to try and help you work on that. With an Access Cab I think that there is more potential for improving fuel economy than there is with a DC. In the meantime you could start by adding a Throttle Body spacer from the website you link to.

[highlevel]

Originally Posted by Highwaylizard

22- 24 MPG with DC is phenomenal!! Now I feel totally inadequate.

Hey Highway,

Don't... it lasted all of about 5 minutes and I probably had a tailwind.

My best average by tank mileage for the DC so far was a little over 16 and I usually don't get that. Too much stop and go, short trips, hills, and not paying enough attention to the foot. That was one reason I got that scangauge. To see how and when I can really make the difference. For me it seemed like the most inexpensive attempt at fuel economy... but then I do own a truck. I know I can't expect much since it is my work truck/daily driver. I have contemplated an economy car purchase but then I have the whole two vehicles to insure yada, yada, so it would not really pan out unless I got a super sweet deal on something fun and economical.

I never got very good mileage in my 03 AC and I had that one for 5 years. I think the best I got in that truck was about the same... 16... going down hill ... so it sounds like you are doing some good stuff.

Good times with your son... spend as much time as possible there (I am sure you know that already). I went through divorce just a couple of years ago and still kind of getting over it. My daughter is 5 and I spend as much time as possible with her. I know that soon it will be her telling me to give her some space but until that time I am taking all opportunities to be with her. Her mom limited my time to two days per week (and it is not worth fighting for more because you know how ugly it can get) but there is a lot of extra time I swing in. Hope things are going well on that front!

Also curious, what happens if that electric fan goes out... SOL? That is what has me hesitant on that mod but I have read people feel like they have had good results. That plus the underdrive pulley, plus headers, plus exhaust. Lots of money, maybe just spending it on gas is fine.... NAH Now what fun would that be??

[Highwaylizard]

Originally Posted by JBK23

Seem like the little green shifter light has gone out on your truck !

Yeah, it is a little annoying but time right now is pretty limited for me so it will just have to wait. I just pretend my truck is "personalized."

Originally Posted by 2000tundra2wd

so is 75 the speed you see the best MPG? it seems that most people on here get the best at 58-65

I think at a lower speed the MPG's would be even better but around here if you do not run 75 MPH on the highway you will get run over. Besides, my research, development and testing is meaningless to most people if I cannot demonstrate that I can at least keep up with the majority of traffic.

Originally Posted by Stan412

I am looking forward to your electric fan conversion. Which one are you leaning toward? I want to do this mod as well and am looking at the Flexalite 775 made for our Tundras.

I have not made a decision yet. I am going to try and get the truck paid off first, get some bills paid down, make it through the summer, and do a bunch more research. I am seriously considering asking perma cool or flexalite to sponsor my testing by providing a unit to install on my truck. It is definitely something I want to do.

[Highwaylizard]

Originally Posted by ianfromdaygo

if im driving on the freeway only
long trips 60-65 mph
my truck will get 250-260 on half tank
the best ive gotten so far is 22mpg
driving from stockton down to san diego

Wow, those are some really nice numbers. That five speed transmission and variable valve timing really make a difference. I may make a run at 60 MPH to see how the numbers return but I am worried about getting run over. People around here like to run out hard on the highway. Not that I am complaining as I like to run the truck out with the rest of them. I know that the faster you run the more power (fuel) it takes to do so.

[Highwaylizard]

Originally Posted by highlevel

Hey Highway,

Don't... it lasted all of about 5 minutes and I probably had a tailwind.

My best average by tank mileage for the DC so far was a little over 16 and I usually don't get that. Too much stop and go, short trips, hills, and not paying enough attention to the foot. That was one reason I got that scangauge. To see how and when I can really make the difference. For me it seemed like the most inexpensive attempt at fuel economy... but then I do own a truck. I know I can't expect much since it is my work truck/daily driver. I have contemplated an economy car purchase but then I have the whole two vehicles to insure yada, yada, so it would not really pan out unless I got a super sweet deal on something fun and economical.

I never got very good mileage in my 03 AC and I had that one for 5 years. I think the best I got in that truck was about the same... 16... going down hill ... so it sounds like you are doing some good stuff.

Good times with your son... spend as much time as possible there (I am sure you know that already). I went through divorce just a couple of years ago and still kind of getting over it. My daughter is 5 and I spend as much time as possible with her. I know that soon it will be her telling me to give her some space but until that time I am taking all opportunities to be with her. Her mom limited my time to two days per week (and it is not worth fighting for more because you know how ugly it can get) but there is a lot of extra time I swing in. Hope things are going well on that front!

Also curious, what happens if that electric fan goes out... SOL? That is what has me hesitant on that mod but I have read people feel like they have had good results. That plus the underdrive pulley, plus headers, plus exhaust. Lots of money, maybe just spending it on gas is fine.... NAH Now what fun would that be??

Hey Rob,

Thanks for the advice/encouragement with my current situation and the importance of being here for my son. I know it is a tough time for everyone but he deserves better.

As far as the electric fans from what I understand they are pretty reliable nowadays. The weak link is the controller and they have improved vastly over the past couple of years. Many manufacturers (primarily those who made the transverse engine vehicles) have utilized the electric fans for years (some for decades) without complications. I think I read somewhere that you can set the thermostat for summer or towing and then re-set it for winter driving. It would be nice to have that type of fine tuning ability.

I think I may test out the Throttle Body coolant bypass for the summer to see what happens. Worth a try.

[LUMP]

I drove from Indy to Tell City this past weekend. Drove 377 on 19.2 gallons. I have an 01 4x4 AC. This is probably the best I have done. I typically average 16.9 mpg on a mix of city and interstate. This weekend I changed the oil about 2 hrs before we left and I also filled up with premium.

[skinny2]

I've been close to pegging 20mpg the last couple weeks on my normal commute. I typically get 18ish on my way to work (17 on the way home) but a couple weeks ago filled up at Sheetz and my mileage (and power) instantly jumped for the two tanks I ran. Had to fill at a Marathon last friday on the way home and this morning I was back to 18mpg. This is all according the the current calc. on the scanguage. My return trip is almost always 1mpg less regardless. Sheetz station is out of my way but I will try to buy there again and see if it jumps again. I've never seen much of a difference between brands...I bounce between Shell, Fuel-mart, BP, and Marathon regularly.