Ive had multiple engines (.21 and .28) in my 6 buggies over the years and the best engine by far has been the Gotech .21 3port...Its hands down the best bang for your buck.Promise guys.Ive ran an amazing 14 1/2 gallons through my H7 TQ.I have a Losi 8ight with a Rossi Mamba a CEN Matrix with O.S. 21 and a MBX5R with a RB Concepts .21 and do not get the performance or life that i did out of my $130 Go tech .21 ..Also,the 5 port is only $160 and is retarded fast.Hope that helped someone.