engine 拉动经济的引擎

造句

投资、消费和出口是拉动经济的三辆马车。
Investment, consumption and export are regarded as three engine of economy.

人们生活的主要矛盾已经从解决温饱转变为对美好生活的向往。。。（我这是觉悟多好）
Many years ago, Chinese people were driven by having enough food and clothing, whereas today their engine is the good life.

翻译

过去几年投资是中国经济的引擎，现在主要是消费在拉动中国经济

The engine of China economy is investing at past, but consumption now.

China's economy，不是China economy
投资investment
前面应该是用was，与现在时态是不一样的，不能这么简单的用but 把两个名词连起来吧。

While investment was the engine of China's economy a few year's ago, today it's many driven by consumption.
In the past few years, China's economy was driven mainly by investment, whereas today its engine is consumption.

查字典

consumption /kən'sʌm(p)ʃ(ə)n/ 消费

investment 投资，不可数名词，/ɪn'ves(t)m(ə)nt/

whereas /weər'æz/

but: 口语常用词，语气较强，泛指与前述情况相反。
however: 表转折关系，语气稍弱于but，连接性也弱一些，因而常作插入语。
still: 语气强，多用于肯定句或疑问句。指尽管作出让步，采取措施或表示反对，但情况仍然如故，无所改变。
yet: 常用于否定句，语气比still稍强。指不管作出多大努力或让步，仍达不到预期的结果。
nevertheless: 指尽管作出完全让步，也不会发生任何影响。
while: 表对比，一般可与whereas换用，但程度弱一些。
whereas: 表对比，一般可与while互换。