would you get better mpg......... (unhook the cruise control vacuum line?)
 

would you get better mpg if you unhooked the vacuum line to the cruise control?

Not really. CC isn't on normally. Normally unhooking a vacuum line causes the engine to run lean unless an oxygen sensor is in the system, most cars built in the past 30 years will have an oxygen sensor. Leave the CC hooked up but don't use it.

good point what about unhooking it and plugging up where the line was?

Nope.

Unhooking it and plugging it will only help mileage if there's an existing vacuum leak in the system. Basically, if your cc system is leak free it already acts as a plugged vacuum line until you use it. And even then, if you do use it, your car will lose vacuum pressure for about half a second as it is set and then it acts as a plugged vacuum line again

oh okay got ya