How many peak amps do I need to jump-start my vehicle?

For most gasoline cars and light trucks, a unit in the 900–1700 peak-amp range is plenty. Larger gas engines and diesels benefit from the higher cranking reserves of dedicated heavy-duty boxes. Note that 'peak amp' figures are marketing numbers; sustained cranking ability and battery quality matter more than the headline rating, and verified-purchase reviewers consistently reward units that hold up to repeated use.