Lately when I start up the car in the mornings the car starts up fine, but once I get going the car starts to jolt back and forth. It feels like the engine is loosing power, or the transmission is having a hard time shifting. Usually it was always while switching from first gear to second gear; around the 15-20mph mark. Today the car did it again but it kept it up even through the third gear and even at the 60mph mark. This is not a daily occurrence and it seems to have started up around the time when the weather started getting colder, but this might just be a coincidence. I have been told that it could be a number of things, but these were just opinions.