MPG Mods

So your engine is now turning 23% slower which means your speedo reading will be off...by how much you can compare by timing with 3-4 mile markers on the interstate. You may find that your speedo is reading slow, which means, for example, if you set your cruise at 60 and went through 3 mile markers at an average of 55 seconds, you actually be doing 69 MPH and have a 9% error. Then you add that 9% to correct your Odo reading on refuel by that percent. So if you drove 200 miles on your odo, you'd add 18 miles to that and calculate your gas mileage on 218 miles, not 200.

I think if everyone who swapped out factory tires for larger ones would find that there mileage, especially on the highway, isn't that much worse off. Around town, yeah it would go down due to the final gearing change and tire mass. Check out your speedo error and add the correction factor. You may be better off than you think. FWIW...

 

i switched all my Gear oil and Tranny oil to synthetic blend and always use synthetic motor oil. I put my tires up to around 33 PSI and i have a K&N air intake i am getting about 22.5 MPG in the winter months here in WV

Thinking about adding a Dynomax Super Turbo Exhaust

 

That's the next step for me too. I put Amzoil in the trans and rear diff on my Gen 1 Taco and picked up 1-2 MPG in the summer and 2-3 in the winter. The trans shifted much more smoothly when cold afterwards. 22.5 is really good for a 4X4 considering there's not a lot of "flat" land in WV like in IN. I'm kind of kicking myself for passing up a nice 2005 with 73K at Carmax for $13,900. Oh well...maybe the next time.

 

yeah alot of mountains here makes for fun driving, but takes a toll on everything (working the suspension components hard and motor and transmission), I found that after everything was said and done the single best thing i have done for gas mileage is simply keep the RPM's below 2k RPM at all time right now i have went 152 miles and still have not dropped below 3/4 of a tank

i wonder if an exhaust would help any at all.

 

That I don't know. I've heard others on this forum say the price of the exhaust won't offset fuel savings. I don't know what's available and what it would cost to do the whole system with a header, etc. I need to save my pennys for my 68 Mustang Fastback restoration.

 

well new mileage to report 23.5 MPG and that is being extremely light on the gas! it makes a huge difference!

and yeah same here i am working an a Honda CRX project car

 

Im wondering whats the best cleaner I should use..... and should I pour the cleaner in before or after I fill up my tank? I know to most people its probably common sence but I have just heard a few people tell me different things. But none of them has a tacoma. BTW I have a 2005 tacoma 2 wheel drive double cab.

 

you know i have been useing lucas oils,gas additive.about every 6 fillups and it seems to do a good job.i have a 99 with a 2.7 and it runs like the day bought it...

 

I've used seafoam with good success. Put the additive in before filling the tank. Then the additive will be equally mixed. I do a treatment every oil change and my vehicles seem to do just fine.

 

Yes, your speedo will be off the same percentage throughout the range. So 15% at 30 will really be 31.5 MPH.

You may not be getting exactly the same MPG as before. The "contact patch" of the tire on the pavement will be larger and thus create more rolling resistance. FWIW...

 

My '10 Access cab prerunner, 2.7, 5spd, w/ 15k miles just went 390.2 miles on a tank in mainly city/town-to-town driving. Stock 245/16 Dunlop tires, everything else is stock except removal of secondary air filter. 18.02 gallons = 21.6 mpg.
Not as great as I'd hoped & I'll be interested to see how it does on the highway during my next road trip.
Some may find this excessive, but I'm going to run my tires are at 40psi to see if this changes the mpg at all. I'll be replacing tires w/ 265/75/16's soon, so I don't care about excessive center tread wear. I know how different my mt bike tires feel at 32 psi vs; 40 psi & I'm sure it will change the tacoma's mileage.

 

Mine is the exact same config and since new I've seen a slow creep from just over 20 to just above 22mpg today with 24k miles. I too have removed the 2nd filter, I use 0-20W mobil 1, and I trimmed my mud flaps down to 4" all around. I keep my tires at 34 psi; I think you'll get better mileage too but I wonder how much lower your tire life will be at 40psi.

 

at 40psi. I would think the center of the tread will be bald and the side will be like new. Not tomorrow morning but eventually.

 

My stock tires say 51 PSI max and I always keep mine filled to 46-47 PSI.

 

Word Andrew, how's that working for ya? I bet you get damn good mileage.

OK here goes gents; I've spent a few days now at 40 psi & don't notice much difference in terms of braking distance, tire roll over in cornering, a harsher ride, or road-bump noise. In short, it's working well for me.

So I'm also starting to understand why the low to mid-30's psi is recommended, primarily for safety, and as a good general use compromise setting, by the car manufacturers for numerous reasons; If you travel bumpy & unimproved roads, or dirt/gravel roads, or snowy roads, as well as pavement, then obviously higher tire psi(>34psi) is more susceptible to sliding, etc. A lower inflated tire brakes better in mixed terrain, absorbs road irregularities better & likely wears more evenly, unless you're cornering aggresively a lot. The manufacturers spec for the lowest common denominator; that grandma driver that needs 32psi tires to be, & feel, safe. One word; liability.

So it all depends on driving conditions. Most of my driving is on very smooth, dry, CA. roads & I don't think low tire psi is really necessary. I'm curious to know how much, & at what psi, it adversely effects my braking distances though. When I think about how much easier it is to pedal high psi tires than low psi tires, I can't help but think the lower rolling resistance increases mpg a lot, and improves acceleration. I think higher mpg's will be even more pronounced in highway driving. My taco weighs 3,620 lbs(just weighed it) & I've got to think pushing 33psi tires would cause it to burn more fuel. At 40 psi I'm also able to take a 90 degree offramp at higher speeds now, and with less body roll & understeer. Hmm.

On the other hand, a high psi tire that has less grip tends to wear more quickly due to frictional scrubbing, than a tire that is hooking up 100% of the time. So I likely need to rotate the drive tire more frequently to offset greater wear. Trouble is, my question/answers have little emperical eveidence to support my assumptions, so I'd enjoy seeing some data or studies that examine the effects, neg & pos, of running higher psi's.

Bottom line is, I used to run 36-38psi on my 4runner & thought I might be too high, but now I'm thinking that for my conditions, 40 psi(or??) might be totally appropriate for a 3,600 lb truck riding on 245 width rubber. The one thing I'm starting to feel convinced of, is 33-35psi is too low for my driving style & conditions. Curious to hear the collective's wisdom here though.

 

holy crap man,

is your truck a 2x4 or a 4x4

 

Deo1929:

15% of 30 mph is 4.5 mph not 1.5 mph. Your seem to be doing a lot of calculations wrong.

 

I've been doing that since day one with my tires, and they don't seem to be wearing unevenly or anything. I rotate them every 7k miles or so. The ride may be more harsh...but I can tell when my pressure starts to drop because I don't coast nearly as far. I've averaged better than the EPA highway estimate for the life of the truck (see signature).

And I don't like mushy tires, especially since I routinely haul fairly heavy loads (for a Taco). Last weekend I had 1700 pounds on it.

 

Should have an answer by 3/18/11 if it fits.

 

^i'd also like to know if i can buy one for my '11