Fuel Efficiency and the Yaris

[Nigal]

I'm a bit perplexed. I got right at 40 mpg one tank full. Then I changed my oil to Mobil 1 0W20 and cut my driving speed by 10 mph and got 42 mpg. I inflated my tires to 44 psi (max sidewall rating) and now I'm back to 40 mpg. Don't get me wrong, I'm not going to bitch about 40 mpg but I think I'm going to deflate my tires back to where they were and see what's what. I know it sounds silly to bitch about 2mpg when over the whole tank that's what?; $1.50 worth of gas? LOL!

[churp]

Originally Posted by Nigal

I'm a bit perplexed. I got right at 40 mpg one tank full. Then I changed my oil to Mobil 1 0W20 and cut my driving speed by 10 mph and got 42 mpg. I inflated my tires to 44 psi (max sidewall rating) and now I'm back to 40 mpg. Don't get me wrong, I'm not going to bitch about 40 mpg but I think I'm going to deflate my tires back to where they were and see what's what. I know it sounds silly to bitch about 2mpg when over the whole tank that's what?; $1.50 worth of gas? LOL!

I'd give it a few tanks then average....so many variables are out there---wind/temp/different routes/how the tank was filled. Mine varies from 40 to 42 even when I think all things are equal.

[keesue]

Originally Posted by Nigal

I'm a bit perplexed. I got right at 40 mpg one tank full. Then I changed my oil to Mobil 1 0W20 and cut my driving speed by 10 mph and got 42 mpg. I inflated my tires to 44 psi (max sidewall rating) and now I'm back to 40 mpg. Don't get me wrong, I'm not going to bitch about 40 mpg but I think I'm going to deflate my tires back to where they were and see what's what. I know it sounds silly to bitch about 2mpg when over the whole tank that's what?; $1.50 worth of gas? LOL!

Actually, its counter-intuitive that a lower pressure will result in better gas mileage. I set mine to 32psi per spec and my mileage increased. It also rides better. Hope that helps. I am going to switch to full synthetic. I have always noticed an increase in my other car(s) when I did. I think I'm going to run Royal Purple given its outstanding sheer-reducing ability.