My zd30 was sluggish and noisy from when i bought it i ran some diesel power through it and it made a noticeable difference in noise and a slight performance increase. The power has slowly improved over time. I am running 33" tyres which suck power but the problem is this, i have great initial throttle response at any revs but it does not keep up the power. To keep the power up i have to back off on throtle until you can feel it accelerate and you have to keep feathering it. Also i get quit poor fuel consumption no matter how i drive. It starts easy.