Can anyone tell me if I should drive in D or B in my car, i know it stands for brake but is it better to use or not
If it is anything like the the B mode in the Prius, you want to keep it in D for fuel economy. There the B is for engine braking. The Prius opens up the valves on the engine to allow it to pump air as most traditional cars do while coasting during fuel cut off.
It throws away energy by doing that, which helps in controlling your speed on long downgrades, but not for conserving energy. But check the manual.
Sorry but, I have to agree with Draigflag, read the manual. We just purchased a 2014 Accord hybrid and I wondered the same thing. I read the manual. What "B" does is increases the regenerative braking feature of the vehicle charging the batteries and slowing you down. The MANUAL suggest that you use it going down long hills.
The manual is a joke just like Draigflag , you have to drive it a while to understand the B mode, works great in town with lots of stops and starts. No long hills here, still get very good use out of B mode after I figured it out, with no help from this board.
I've found that using the D mode in the Accord Hybrid is easier to deal with in city driving where you can anticipate the traffic ahead and coast as long as you can. It also is easier to "pulse" drive in the D mode. "Pulse" driving in B mode causes a jerky motion to the car. Using the B mode means you have to stay on the gas pedal until you are close enough to start braking, since it doesn't coast as far. You can start coasting in B mode further away from traffic, but that tends to upset people who follow you too closely, since you decelerate too fast for their tastes. Maybe on the freeway in stop in go driving, the B mode works better, I haven't been in that situation yet - it's my wife's car, so I rarely drive it on a daily basis.
Of course, on downhill drives, it is used to control the speed while taking advantage of energy recovery.