poor performance and fuel economy

[shortdogg1980]

i need some help on my 01 i30t that i recently bought, the car is in good conditon had cats replaced under warrenty, had problems wit my windows that was covered from the dealer also, but i can tell a major difference between the i30 and my previous car (99 maxima se) as for as performance and gas mileage, i'm maybe getting average of 18-21mpg in comparison to 25-27mpg wit my max, and i have a slow accelaration from 0-60, any suggestions on what to check besides tune-up and servicing my transmission which has already been done?

[Beancooker]

Is it throwing any codes? The loss in power makes me think it could me numerous things. Knock sensor, MAF, o2 sensor, what are the exact symptoms?

[shortdogg1980]

not having any current or history codes, car dosent hessitate or stall, just poor accelaration from stop and fuel economy

[Bergerman]

I had similar fual economy questions when I got my '99 I30 in December but I've come to realize that the best I'll get is around 22 MPG. The articles that I read before I picked it up said I should average about 25 but I have not been able to achieve that even with mostly highway driving. (60 ml per day commute) Since I bought it used, I do not have any maintenance history so I am planning on a full tune up in the spring/summer. Maybe that will squeeze out a couple more MPG.