Fuel Trim Reduced MPG

I have a 2016 Tundra and was having the long start issue. I had a buddy reset the fuel trim levels and have noticed a major drop in MPG. Pretty close to the same time I had an Eibach 2.0 suspension and new 275/70/18 installed. I am showing I have around half a tank left and the mile range is showing around 400 left. Actual mileage is a little over 100 with a little over half a tank left. Just curious if anyone else has come across this. Thanks.

 

Is it a flex fuel engine?

 

Codes? Long start could be a few issues like EVAP purge, MAF sensor, etc. which would also impact mpg.

Run some seafoam through the gas at least if no codes and clean the maf/throttle plate.

 

I just reset my alcohol and nothing changed on that. If they also reset all the learning values that might take some time for things to balance out.

 

I can tell you for sure that you lost at least 2mpg with the lift and those tires. Ive run the same exact setup.

Those are 33 inches tall, vs the stock 31.5-32 inch tall tires.....so you cant go by the MPG the truck tells you on the dash. It thinks you are running stock tires.

You need to hand calculate MPG now, and you need to account for the larger tires by adding 3-4% to your actual miles traveled (difference in stock vs new size). Then you do the usual MPG calculation based on how much gas you pump in.

Your MPG will be a little better than what the truck is telling you.

 

It is a flex fuel.

 

Thanks! I will run some seafoam through it. The truck has started up great every time now after the reset.

 

Thanks, glad to hear from other experiences.

 

I definitely love the suspension and the new tires. I figured I take an MPG hit with the new setup but it seemed like more than I expected. Thought it might have been coincidence since I did the reset at basically the same time as well. I am hand calculating now to try and get a better gauge. Thanks

 

As suggested above, reset the alcohol fuel %. Flex fuel motors are prone to creeping ethanol percentages in the ECU, which causes the motor to run rich due to the lower energy density of ethanol. This makes for hard starts and reduced mileage. I'd start there.