I "fixed" my poor fuel economy

[A.Wilson013]

"Cool new thread, Alex. Thanks for wasting our time."

So ever since ever since I have been pretty unhappy with the gas mileage my 4Runner has gotten. Add some bigger tires, all sorts of heavy metal stuff, etc, and it has only gotten worse.

Well, this past Thursday I had to drive to Seaside and thought I'd try to see how good I could do. In preparation I took my tent and awning off. I drove from Dupont, WA to Longview, WA (70mph for the majority of the trip) and fueled up. With the defrost on, and normal driving (ie going the speed limit) I got 16.5mpg figuring in my odometer error (I have "calibrated" my odometer many times and every time it's 7% off). I was pretty upset, that's about what I get on the freeway when I have my tent on.

From Longview, WA to Seaside, OR (Speed limit 55mph with a couple steep grades both up and down, and a few slow downs to 35mph through towns), with the defrost on and normal drive (cruise control set at like 58mph, and slowing down to the speed limit in towns) I again got 16.5ish mpg. Again, pretty upset with that.

So on the way back home I tried something new... I turned off the defrost. Everything else I did the same. Seaside to Longview I got 18.92mpg. I was/am pretty stoked about that. However, I was sure my fuel economy would CRASH once I started cruising the freeway. Wrong. From Longview to Dupont I got 18.65mpg.

I knew that running the AC had an affect on fuel economy, but I had no idea how drastic it was. Before today I ALWAYS had the defrost on (fogging windows drives me NUTS) but from now on I'll just be cracking a window.

I am very happy to get 18+ mpg while cruising the freeway at 70 considering how dang heavy my 4Runner is. I am confident that if I tried I could get 19+ mpg if I stayed under 60 on a flat highway. I haven't achieved that since I ran 265/70/17 P-Rated tires and no lift.


tl;dr Turning off my defrost gave me a 15% increase in fuel economy.

 

[D Farms]

you do know why the odometer is off right? its because you increased your tire size, and there is nothing you can do short of getting new abs rings with more teeth machined that will correct it. mine is off 25% because mine came with the 28" tires and now im running 35s.

 

[A.Wilson013]

18 plus, i'm jealous. i'm lucky if i got 15:Cry:

Lucky if you get 15?! That's pretty bad dude. I only got under 15 once and it was when I had the cruise control at 80mph in Idaho with my roof top tent on top and the back of my 4Runner PACKED with camping gear.

I slowed down to 70 after that.

you do know why the odometer is off right?

Of course I do, that's why I "calibrated" it in the first place.

 

[diverscale]

I've read in other threads that putting ''power ECT'' on all the time for bigger tire users might give off a better fuel economy. You might try this also.

 

[maxbrown11c]

I always have mine set on defrost/feet so the AC doesn't kick on, but my windows don't fog up. Pretty much have to run it like that all the time in these western washington winters.

 

[SilverRidgeRunner1]

I've never used my AC in my 4runner explains a lot..

 

[AZBub]

I have yet to figure out what ECT does besides light up a pretty blue light on my cluster. I experience no difference in power or fuel economy when it's on.

I have learned that 73mph is about as fast as I can go before my mpg takes a poo. I was consistently in the 20-21mpg till I got 265/75r16 poor man Duratracs from Wallyworld.

I enjoy reading posts about the mpg quirks.

 

[I-4x4]

I always have mine set on defrost/feet so the AC doesn't kick on, but my windows don't fog up. Pretty much have to run it like that all the time in these western washington winters.

Pretty sure A/C kicks on even with the defrost/feet combo. Switch from feet only to combo while sitting idle...

 

[ShooterMcGavin]

I always have mine set on defrost/feet so the AC doesn't kick on, but my windows don't fog up. Pretty much have to run it like that all the time in these western washington winters.

That's a good system. Just vent in fresh air and most of the time it works. When it is wet out (hardly ever happens in WA state ), the defroster really helps clear windows though.

 

[ShooterMcGavin]

Pretty sure A/C kicks on even with the defrost/feet combo. Switch from feet only to combo while sitting idle...

That's not true for mine - 1997 SR5 with the slider heat-controls. The AC only kicks on for the full defrost.

 

[calimobber]

BTW i'm a noob but what is ECT power plus do you know what the button on the side of the "gear shift is"?not the one for 2lo/4hi/4lo, but the reverse/drive shifter/

The ECT switch changes the shifting points on the transmission. Mainly it holds lower gears longer so when your towing it makes it easier on the car. I mainly use it when towing since I hate the light on. I mainly notice it holds the shift from 2nd to 3rd to 3500rpm vs 3000rpm.

The button on the side of the main shifter turns off overdrive. also good to turn off when towing or anytime your anticipating a big hill and know its going to downshift anyways.

EDIT: haha I beat ya to it Diverscale :lol: Great minds think alike


As for the topic, yea defrost keeps the compressor on non stop to help remove moisture. I tend to cycle it on when it gets foggy and off when it clears up. I try to keep the a/c off whenever I can for this very reason. Its a mileage killer.

 

[diverscale]

BTW i'm a noob but what is ECT power plus do you know what the button on the side of the "gear shift is"?not the one for 2lo/4hi/4lo, but the reverse/drive shifter/

ECT will use a more agressive transmission shift map. You will upshift at higher RPM and downshift at lower throttle input. I did play a bit with it, and seem to do something only when using high throttle input. Should be used for towing, or when having larger wheels. Some people are stock and do not tow, and leave it on all the time for the increased responsiveness.

The other button must be overdrive off. Your vehicle has 4 gears, pressing this button will cancel-out the fourth gear which is the overdrive. Nice for towing.

 

[I-4x4]

That's not true for mine - 1997 SR5 with the slider heat-controls. The AC only kicks on for the full defrost.

Interesting. I have a 2000 SR5 and when I make the switch, the rpms drop and I hear the a/c clutch engage like it does when I hit the a/c switch..

 

[diverscale]

4 years later, i get the answers i was looking for. p.s.- is that a lotus esprit in your avatar picture?

looking through the maintenance manual, here is the only thing I could find explaining the ECT power switch:

Pattern Select Switch Circuit
CIRCUIT DESCRIPTION
The ECM memory contains the shift programs for the NORMAL and POWER patterns, 2 position, L position and the lock-up patterns. Following the programs corresponding to the signals from the pattern select switch, the park/neutral position and other various sensors, the ECM switches the solenoid valves ON and OFF, and controls the transmission gear change and the lock-up clutch operation.

Yes, it is my lotus esprit, 1991 SE . and behind, my last 4runner which was a 2013.

 

[ShooterMcGavin]

Interesting. I have a 2000 SR5 and when I make the switch, the rpms drop and I hear the a/c clutch engage like it does when I hit the a/c switch..

Yeah, I can understand the thinking on both sides. If I switch to defrost, the AC comes on. If I switch from defrost back to defrost/feet, the AC turns off. That's just on my '97. Not sure about other years.

 

[Tyota89]

Im going have to test this my next trip down to OR, 14-15 is a little sad. Was doing 18-19 when I first got it.
Need to invest in some rain gaurds.

 

[99Runnr]

I got 20.95 my last tank of freeway driving. That's at 60-65.

I'd be super happy to get 19 lifted that much man. Usually I get 18-19 mixed though.

 

[SpidermanGeek]

4 years later, i get the answers i was looking for.

4 years? You mustn't have been looking that hard.

Let Me Google That For You

Also..

You can find Owner's Manuals for download too!

 

[mountainbiker42]

I call it the go fast button. Although its great for trailering loads, I turn it on when I wanna beat someone from a line or get the cobwebs out

 

[mountain mike]

I don't run my A/C or defrost and I only manage 13 tops, seriously 13 MPG MAX. That is with 33's, TR's, and 4.88's. I am at 6,000 feet, I am sure that plays into it, but I would be ecstatic with 16.5!