Hi...I'm new here.
I walk 30-35 on the TM, several days a week. I walk mostly at a speed of 4.3. I mix it up with a rate of 4.8. Is the rate of 4.8 jogging? Would I burn more many more calories if I did the entire thing at 4.8?
Thanks.

Alternating your speed is a great way to gradually get into jogging/running...

I feel that running burns calories a lot more than walking, there is a lot more intensity involved in running... But if someone can't run because of knee problems or whatever, brisk walking is an excellent cardio. Moving in any manner is better than not moving at all...