This may be an insignificant question, but here it goes. While using my cruise control, I slow down and stop at a light. Is it hard on the engine to use the resume button to bring the car back up to speed and would it be better for me to bring it back up to speed myself, then reset the cruise control? Your opinion will be appreciated.
You cannot start off from a stop using the cruise control (new technology may differ). The vehicle must be above thirty mph before the system is operable. This is a safety feature. The use of "resume mode" to bring the vehicle back to its previously set speed uses fairly aggressive acceleration. As far as this process being hard on the engine is concerned; the harder you stomp on the gas pedal the more wear and tear inflicted. However, looking at the rate of acceleration and the small amount of time in the resume mode, I would not consider this abuse.
So my advice to you is, if you are a very particular, mild driver and the acceleration during resume greatly outweighs your normal driving style, go ahead and bring it up to speed yourself. Then use the set or resume switch when you're almost back to the previously set speed.