Put a set of OE 20s on the L with 295/40/20s and now my gas mileage sucks. Not sure if its a coincidence or if the computer needs a chip or something. Any ideas?
Thanks in advance
Dave

 

It prolly is the rims since there bigger, 20s do weight alot. Same thing with the tires since there bigger to fit the rims.

 

Just wait. Some jack will pop in here and tell you to buy a honda if you want gas mileage. I agree with Big Man though. More rotating mass and all that.

 

Buy a Honda if you want gas mileage.
-jack

Seriously, 20s add a huge amount of unsprung weight to the truck, making the engine work a little harder and thereby reducing mileage. I wouldn't think it would make that big a difference, though.

 

your speedo if off due to the bigger tires/wheels.When your speedo reads 60 you are actulely going 61.8.

You went from a 89.4 tire circumf.to a 92 tire circumf.


try this site http://www.miata.net/garage/tirecalc.html

 

Now that I have more weight, I'll just have to add more power to turn it more efficiently. Yea that sounds good. Which chip to get? and how often should this thing need plugs? It has 25800 on it and most of it has been pulling a 21' Storm Bass Boat.
Thanks
Dave

 

These trucks actually get "Gas mileage?"

 

What's THAT?

 

It's the number of gallons you can burn per mile...

 

According to this calculator:
http://www.discounttiredirect.com/di...foTireMath.jsp

You speedo error is 1.92 at 65 MPH. Less miles = greater distance. (compared to F1 295/45/18

I ain't never been good at math so I use cheat sheets and calculators whenver possible.

I know that error is not straight across the board but maybe one of these smart guys can figure it.

As far as unspring weight goes? It would be interesting to know some accurate numbers for a stock rim and say a F1 tire.

Unsprung suspension weight hurts you in the ruff when it comes to handling and ride comfort. It takes more inertia (HP) to get things turning but ounce you get that mass going it has a flywheel effect.

 

I wish!

 

I got 16.4 on the hwy this last weekend and it wasn't downhill with the enging off.

 

I am back to 15-16 mpg. My problem was probably some bad gas as it cleared it self up. Oh and I have 295/45/20 tires with the heavy HD rims.

It must be my camper top...