Well there is no such thing as a big 18g but there are 18g tdo5h and tdo6. The big 16g will have the quickist spool up,but the least power. tdo6 18g will have the slowest spoolup , but most power.The tdo5h is between them. Its very streetible and once is spools your like it
. Anyways what would you use your car for mostly?