If the car is heavy the tubes will help stiffen up the tire. I run a stiff sidewall goodyear because my car weighs 3200-3300 with me in it. Again,same as before...I run the stiff sidewall because people that I trust told me to.I have never tried any other tire .
The car seems to squat on the tire more since I took the tubes out but that might just be my imagination, who knows.I use the same tire now that I used with the tubes. 32-14 goodyear D5 COMPOUND D1984