slight hesitation when stepping on gas pedal

Without feeling it myself, it all is going to depend on your interpretation of a hesitation, compared to mine. First of all, is there a check engine light that coincidentally came at or near the same time this started occurring. Check and verify the oil level is not too low, if it reads on the indicator stick it is not. Does this hesitation continue under load(i.e. misfire)? With the newer electronic throttles, if you stab the pedal somewhat rapidly, there is going to be a slight delay, that is normal.

there is no check engine light on and the oil level is fine. It happened today and there was no load in the car. I was going to add a gas additive to see if that works. what do you think.

Usually if a condition is already present, an additive will have no affect. Additives are marketed to perform miracles, but often times are a preventative at best. If there is no check engine light on, then it is safe to assume that the powertrain system has not seen a problem. This does not mean that there is no problem, just the specific criteria to set a fault may have not been achieved.