Civic city driving, D3 or D?
 

Hi Group,

I am an owner of a 05' Civic, which comes with an auto transmission. I
have always been driving with D, until I accidently read about the D3
shift yesterday.

The owner manual claimed that in stop and go situation, driver should
put the shift in D3 so that the trans will not be shifted to the 4th
gear. This makes sense to me. However, I still wonder if I should do
this in my case.

I drive about 8 miles each way to work. There are several cross
sections so normally I would be stopped several times. However the city
speed limit here is relatively high (40mph). When I put the shift at
D3, at a speed of 40mph, I feel the engine does not have much more to
give.

I wonder if there is a maximum (proper) speed for the third gear. I
have never driven a manual car before so I honestly have no idea.

Also just for the sake of curiosity, at 40mph, which gear will yield a
better gas mileage per gallon, the third gear or the fourth?

Thanks a lot!

Regards,
Doug