Hey everybody, I'm a newbie to the world of fuel conservation. I sold my '01 Accord in early July and bought an '03 Toyota Echo a few weeks later. I thought I did my homework on this one and yet it seems I bought the only Echo that could get 28mpg on the first tank (one tire was low) and still only 30 on the second. (Avg=34.5) I do 60-70% stop & go but so does everyone else in my area and still they get 35 or more. I need help! I'm sure some of the increase to 30 was an improvement in my driving but this is still bad, especially for an Echo.
Here's the facts. The young guy I bought it from did a customization job on it. Anyhoo, he added an Injen intake for the air and a large exhaust which I put the silencer on. An exhaust guy told me big loud exhaust lowers back pressure and speeds up the revs. The wheels are 15" and tires are low profile performance P195/50R15's when stock should be P175/65R14's which are both taller overall and in the sidewalls, with narrower width. The tire size calculator shows 917.5 revs per mile now vs 906.3 stock. The current tires call for 44psi and I check them regularly but I don't know what stock would inflate to.
So what gives? Should I invest the dough in stock wheels & then tires from Costco (with nitrogen)? Does it increase by 4mpg like that guy on epinions says? Do the tires really make a difference? Does fat exhaust help or hurt? Do I just give up & sell her and wait for a "normal" Echo to come up for sale? I'm curious as to what y'all would say as I intend to do everything possible to reach the magic 35mpg, whether with this car or another one.