Lifted folks; you may not be getting as bad as MPG as you think.

When I went to 285s, my gas mileage took a nose dive. Computer showed my average going from mid-18's to mid-16's.

So I filled my tank, re-set the trip meter, and then checked my distance traveled using GPS. I found that for every 10 miles that the trip meter showed that I drove, I actually drove 11 miles. This was due to the larger tires.

So I just drove 196 miles per the trip meter, then adjusted the miles to a more accurate 215.6, then filled the tank, which took 11.49 gallons, and found out that I averaged 18.76 MPG over the past week, rather than the 16.6 mpg that the computer was showing.

Not a huge difference, but it made me feel much better about my mpg for an upcoming road trip to Arizona and back.

 

Good to know. I’ll track my mileage with a GPS to calculate my mpgs. I currently average 15mpg with 285’s. But I don’t feather the throttle either.

 

Is it possible the stock tires were overstating your mpgs in the first place?

 

Mine shows 16mpg, so I figure I’m closer to 17mpg since that 295’s are a significant jump from stock. Even if it were spot on I’m happy with 16mpg on 295’s haha.

 

It's odd, Toyota must sub out parts to different places. My runner is 100% spot on with 285s checked with radar and gps.

 

You guys must coast downhill. I have never seen more than 14-15.

 

I have 285/70/17's as well. My odometer and speedometer are completely accurate. A 285 is about 3-4% larger than the stock 265's.

The speedometer reads high with stock tires. With 285's, you should be accurate. Every tire is a little different, so there will be some variation.

My computer has shown a loss of about 1 MPG after the lift and tires. I'm pretty happy with that.

I also don't trust the computer, and check my fuel economy at every fill-up. My actual mileage has been anywhere from 14.5 to about 19 since the mods.

 

I've only been below 15 once, and that was with 285's and driving it like I stole it.

 

Where I live is full of hills, constantly on the skinny pedal. On trips when crushing on the highway the best I’ve had is 18.5mpg, per the computer.

 

90% City driving during the week I average 15-16 with 285’s and my speedometer is 100% dead on with gps and Knox county sheriff dept

 

I got rid of the stock tires within a a month of buying the 4Runner. With stock tires, I was getting around 20 mpg average.

I replaced them with 10-ply E-rated aggressive and heavy tires in the stock size and added a roof rack and saw my mileage drop to the 18's. My GPS showed my actual speed was about 2 mph less than what my speedometer showed. With the 285s (which are 32.9" tall), the speed is shown as 1 mph faster than what is shown. Hence, the 1 mile for every 10 miles adjustment.

Another factor in my region is the introduction of "winter blend" fuels. About this time of year, the fuel companies start replacing the summer gas with fuel that is lower butane rated that supposedly reduces emissions. The purpose of that is due to the increased instances of air inversions in communities in the mountains. This results in another 5% to 10% drop in fuel efficiency this time of year. Couple that with lower ambient temps and I have seen around 2 mpg lower averages for the winter months.

 

I am glad to hear this. My city MPG is now between 14-15.... Highway only is still around 18, but hardly get that in Los Angeles County....

 

The trick is to coast uphill

 

If your speedometer and odometer are off by 1 MPH at 10 MPH, you would adjust by 1 mile for every 10. But, if you're off by 1 MPH at 60, you should only add 1 mile for every 60 driven.

This is true. Winter kills mileage. Aside from winter blend fuel, the cold weather affects it as well.

 

Do they use winter blend gas by you?
They do in Chicago and every year around November I consistently lose 1-2 mpg from it. This spans many years and many different brand vehicles.

 

It's not just winter blend fuel, though. Cold weather affects fuel economy as well

https://www.fueleconomy.gov/feg/coldweather.shtml

 

I have not checked mine yet since adding 285’s. Just going off what the gauge says. When I get a chance I will check into it. Not really worried about the gas mileage. I also do know I’m not running a sprint booster and I don’t have a problem with power lost. My Pro pulls out fast enough. And even when I need to step it down on the highway.