I used to have a 2003 Lancer which would benefit quite a bit from the Seafoam treatment, and it was easy to do. There was a vacuum hose right on the top of the engine, I'd unplug that, let it suck in half a can of Seafoam, let it sit for a few hours, then go for a drive. Don't have the same vacuum hoses on the top anymore. Whats the best way to give my 2013 Lancer GT the Seafoam treatment? I never had great luck putting it straight into the gas tank, it was putting it straight into the engine that really made the difference. I'm about to roll over to 80k miles, engine hesitates sometimes, power seems to be lacking a bit, so I think it's Seafoam time.