The orderly performance of the market ensures equal competition and fair trade, protecting the legitimate rights and interests of producers and operators and consumers. Valuation bubble Medium small Springall said: "this will be a long time before fully recover energy saving market also so if savers, waiting for a long time, they may eventually in some we saw in more than a year the most preferential price missed." It is generally believed that the v-shaped engine is a relatively advanced engine, which also becomes a symbol of the sedan grade. At present, the most common engines are the straight-line 4 cylinder (L4) and v-type 6 cylinder (V6) engine. In general, the V6 engine has a higher displacement than L4, and the V6 engine runs smoothly and quietly than the L4 engine. A V6 engine is usually mounted on a mid-grade sedan.