英语 我以为.“I thought.”和 “I would have thought ” 的区别

英语 我以为.“I thought.”和 “I would have thought ” 的区别
英语口语对话时,当真实发生的事情跟自己认为的不一样,I thought(我以为）+虚拟语气.
今天在字典里看到个句子：I’m surprised he rides a motorbike.I would have thought big cars were more his style.没想到他骑的是摩托车,我还以为他喜欢大轿车呢.
请问,都是表示 我以为 ,“I thought” 和“I would have thought ”用什么区别,在使用上?
没用过后者,在表示 “我以为”时 ,我都是用 I thought