Sentences with comparisons

something is similar A=B

Our car is as fast as Peter's car.

Something is not similar A≠B

Use not as … as (to say that something is not similar)

John's car is not as fast as our car. (A≠B)

Use than (to say that something is bigger or smaller)

Our car is faster than John's car. (A>B)
John's car is slower than our car. (A<B)

NOTE!