[DrG]

You have had some good replies so far but I'll add my two cents. I have a 21' Tige and while I know it's there while on the road, I have plenty of power to cruise 65 to 70 with it. If your dealer isn't helpful, try an independent garage. Have them hook it up to the computer and see what happens. Maybe you are dropping a cylinder or two under a load. The mass air deal could be a problem but it wouldn't hurt to replace the plugs due to time, instead of mileage. I've had plugs go bad that looked good but not in these newer high voltage engines. The trailer brake thing was a good idea. Will your trailer roll back and forth by you just pushing it? One more thing, I just got mine out of the shop for a diff leak but I mentioned to the mechanic that my gas mileage had been dropping off for the past couple of tanks. He reflashed the PCM with the latest update and I'm back up better than it was. You might ask about that. I wasn't aware they were updateable.
David