normal gas milage?

I'm new to this form, and have a question for all you junkies out there. I have owned three tacomas and have loved every one of them. I have an 07 double cab 4x4 off road, in a manual trans. I bought it new and was getting 18-19 mpg. I put my exauhst, drop in filter, and my lift wheels and tires on, all on the same tank of gas. My milage dropped to 12-13, and then came back up to 15. I cannot get more than 15-16 out of it! (16 if I'm lucky) My tires are 285/16 with an 18" wheel. I know I should loose a little power and mpg, but 3-4 mpg? I drive 95% freeway, and I am the slowest driver you have never wanted to follow. I stay off the pedal. Is this normal? I had a thottle body sapcer and that did nothing to the mpg, so I took it out. Any suggestions? What do you guys see out of yours? It has 16,000 miles on it now.

 

If you don't get your ECU re-calibrated for the bigger tires your odometer will be out.

 

I did some math and I think he drives the majority on the freeway

 

My 285/76 16 tires throw the speed/odometer off by 7%. That makes it look like I'm getting 16 mpg when I'm really getting 17 (via scangauge or adjusted calculations).

Use a tire size calculator to determine the size difference between stock and what you run now. Then use that to adjust your calculations. Something like:

 

I never thought about that, ill check that and see what I find. Thanks.

 

I checked it, but I'm not sure how to transfer it correctly into how it would affect my mpg. It says I'm only 18 rev/mile less than stock size. Could that much reflect my mileage I'm seeing? I don't know the "ratio" so to speak. my non-stock tires are only 2.8% slower. Does that 2.8% equal my loss?

 

What are the sizes you are comparing? I can put them in the calc and figure it out.

But if your new ones are 2.8% slower than stock, then you are travel 2.8% less than the odometer reads. ie, odometer says 300miles, you've really gone 291.6 miles (300*.028 = 8.4, 300-8.4=291.6). And 60mph = 58.32mph.

The stock speedo is off about 3mph. I've driven passed police radar displays with stock tires. Speedo says 30, radar display says 27. In your case, you'd be closer to 25mph while the speedo reads 30.

If anything, those numbers inflate you odometer readings slightly and you should get slightly better mpg. Then again, it may not be enough to affect them. It would be less than 10 miles per tank anyway.

 

stock i was told is 265/70/16 mine are 285/60/18. it came out to be 2.8% I can't imagine that is the reason for my mileage. The truck runs great just gets 15-16 mpg freeway. Most every one I have talked to that owns the 4.0 gets quite a bit better than that. I'm not sure what to do? Take it as it is? The only gas I put in it is reg to mid grade cheveron.

 

Ok. Got my numbers backwards... When the speedo says 60, you'll be going 61.7, and when the odometer says 300 it'll really be 308.4. So it's showing slightly less miles than you actually traveled. Still, shouldn't affect things that much thought. My 7% difference is still only about 1mpg, and 21 miles/tank if I fill up around 300 miles.

I'm thinking it must be the tread pattern of the new tires. More wind resistance, rolling friction, something.

How long have you had them on? I noticed a loss of torque when I first put my 285's on, but after 30+k it seems to have some back. Like the ECU adjusted something.... Maybe it just broke in more... lol I only had the stocks on for around 8k so it was just starting to really break in at that point.

 

My first tank was interstate driving 70-80 and my new Tacoma got 21mpg.

 

You should be getting about that. You have the smallest cab with the I4... He has a double cab, 4wd, with the V6. Most people with that get maybe 19mpg max I believe. I'm lucky to get 17-18mpg.

 

Ive had my tires on for about 13,000, it only had roughly 3000 miles on it when I made my changes. In my opinion it should get better than it is. So who knows. Before I take it to the dealer I just want to make sure I have some validity, so I don't look too stupid. I'm confused to why I got 18-19 when it was new then the drastic drop in that one tank of gas. I'm just trying to dig for any and all help, but it just maybe thats what the truck gets. I might try driving it as hard as I can every where I go, and the mpg will get better, that makes just as much sense, and its would be a hell of a lot better time.

 

It only dropped for one tank? Bad gas maybe? Or is it continuous over sever tanks?

 

My 2005 v6 TRD PreRunner gets 21mpg pretty much constantly.Took alot of fiddling with my tire psi but I'm happy with 21 mpg.....Oh, and my truck is stock!

 

It took 2-3 tanks for it to climb to 15 mpg. (after the lift, wheels and tires) For the last 11 months I can't pull over 16 mpg on the best day.

 

Just did one for the new year, 265/70/16 BFG's rugged trails, 87 octane ,V-6, 6 speed, 18.69 mpg.

 

I'm with JDB. Have 08 Tacoma Pre runner 4.O Double Cab. Bone stock only got 288 miles out of a tank. Installed 6 in lift w/ 305 tires and only get about 14 mpg. GPS showed to be at 61.7 mph while dash showed 60 mph. Can somebody do the math for me. Truck only has 2500 miles on it.

Wanting to know what else can be done to get better back to what most peeps get at stock (gears, exhaust, air in-take)

Truck shows to have 3:73's. Am i correct??? Would i be better off going to 4:10's or 4:56's. This truck is not my play one, want normal as can be driving conditions .

Thanks,

Craig

 

The lift and the 305 tires are eating all your lunch money, it's something we hear all the time, fooling with the truck really does affect it. Let the truck "break in" between 5-8000 miles then retest your milage. As for the diff. ratio, I would think you would have 4:10's, should be on the window sticker if you still own it.