1.do the mini 1/18ths run longer then 10ths?
2.is there a way to go over 1 hour run time with rc18mt if so what need?
3.can 1/18ths go thru backyard small grass and dirt?
4. is mamba the best motors and esc for the 1/18ths?

Wow... so many questions...

But that's ok. Longer run time is accomplished with gearing and type of battery.

A 1/10th scale car with a stock motor and a good set of 3300 mah batteries (or 3700's) can run a long time on a single charge if it's geared to slow down the top speed and go for run time.

Most of the 1/18th scale cars I've played with using the 1100 nimh packs will run about 20 minutes when geared right, and still have ok speed. The Li-Po's seem to have longer run time, but I haven't played with any of those batteries yet. A brushless motor I am told in conjunction w/ Li-Po's will run a really long time too but where I run we still use the brushed motors in racing.

The only problems I've had with my rc18t in the yard is it picks stuff up and lodges it in the gears. I've heard if you remove the cover under the gears this is reduced. (Mine is mainly running on Carpet)

Check out:

www.maxamps.com (http://www.maxamps.com)

They have lipo batteries and I think for your application if not they can make them.

They have a good conversion kit for about $100 or so.

mc

LIPO and a mamba you will have some long run time