Learn Swedish: Jag håller ratten så hårt som möjligt. - I hold the steering wheel as tightly as possible.

This is a set construction meaning "as [adverb/adjective] as possible". In this sentence, så acts as the first "as", som is the second "as", and möjligt means "possible". You simply place your describing word right in the middle.

Why is it hårt with a -t at the end instead of just hård?

Because it describes how you are holding the wheel, it acts as an adverb (meaning "tightly" rather than "tight"). In Swedish, you generally create an adverb by adding a -t to the adjective. Notice that the -d in hård changes to a -t to make hårt easier to spell and pronounce!

Why does möjligt also end in a -t?

The base word is möjlig (possible). In the så ... som möjligt construction, it always takes the neuter/adverbial -t ending. This is because it refers back to the general action of holding the wheel, rather than describing a specific "en" or "ett" noun.

Is ratten a false friend for English speakers?