i drive a KE55 with an auto 3sp back an forth highways all the time at 100-110 i don't have a problem with the booming of engine noise when i put the foot down, i actually like it when i have to accelerate to over take someone cause it sends a nice mini beast roar which never fails to raise passengers eyebrows, even then its quite comfortable .. you surely will be able to hold conversations so its not bad at all.