How much do larger tires affect gas mileage?

I am looking to get larger tires for my truck. These tires are 35 inches in diameter. Saying that I already change the gear ratio and stuff, how much would it affect my gas mileage?|||larger tires will affect your fuel economy in a negative way because they are heavier and require more energy to move them.





http://www.improve-gas-mileage-guide.com鈥?/a>|||Well it actually changes the gearing in your car so it drans more gas the bigger you go i'm guessing your truck came around 29's stock so it'd affect it 2-5MPG depending on the mods and the motor on your truck My advice is get a K%26amp;N intake to offset the drain from the tires|||for 1 thing it,s slower starting out but once it get,s moving then the tires can cover more ground so about the only way i see you would waste more gas is starting out.|||changing the gear ratio will hurt fuel economy more than the tires|||cant really say til one does it but can say yes it will make it worse