A real driver is pushing it to its limits, and you can see this.
The thing that you can see — the “this”, if you would — is the real driver pushing it to its limits.
The object of the verb see is here the entire gerund clause following it. It’s a gerund clause whose subject is the object pronoun it.
Sense verbs do this: they can take either a gerund or an infinitive. Since neither is a tensed verb form, a pronoun serving as the subject of a gerund or infinitive clause needs to be in the object case not the subject case.
- I watched them playing in the park.
- I heard him calling for help.
- They observed me struggling to find purchase.
- We smelled them flowering at their peak.
- You noticed him coming in without wiping his shoes first.
- The winter wind was awful; I felt it leaking through the cracked window frame.
Using the gerund instead of the infinitive gives it a continuous sense that does not apply to the corresponding infinitive clause:
- I watched them play in the park.
- I heard him call for help.
- They observed me struggle to find purchase.
- We smelled them flower at their peak.
- You noticed him come in without wiping his shoes first.
- The winter wind was awful; I felt it leak through the cracked window frame.