▁and ▁light ▁weight ▁to ▁improve ▁average ▁speed , ▁even ▁if ▁cost , ▁ease ▁of ▁entry / exit , ▁comfort , ▁and ▁other ▁" p ract ical ▁vehicle " ▁attributes ▁are ▁reduced . ▁ ▁By ▁anal ogy , ▁many ▁autom obile ▁mak ers ▁make ▁performance ▁cars ▁with ▁limited ▁se ating ▁and ▁cargo ▁and ▁worse ▁em issions ▁and ▁fuel ▁economy . ▁ ▁In ▁contrast , ▁other ▁vel om obile ▁designs ▁sacrifice ▁performance ▁features ▁in ▁order ▁to ▁improve ▁cost , ▁entry / exit , ▁comfort , ▁carrying ▁capacity , ▁and ▁so ▁on . ▁ ▁By ▁anal ogy , ▁many ▁autom obile ▁mak ers ▁offer ▁cargo ▁v ans . ▁ ▁As ▁of ▁ 2 0 1 7 , ▁individual ▁mak ers ▁sometimes ▁offer ▁models ▁sp anning ▁a ▁range ▁of ▁features — for ▁example , ▁there ▁are ▁Milan ▁models ▁used ▁in ▁racing ▁but ▁also ▁a ▁Milan ▁" c argo " ▁model ▁with ▁enough ▁lug g age ▁volume ▁to ▁carry ▁a ▁( not - ped aling ) ▁human ▁passenger ▁and ▁other ▁bul ky ▁items . ▁ ▁All ▁current ▁( 2 0 1 7 ) ▁vel om ob iles ▁are ▁produced ▁in ▁low ▁volume , ▁with ▁" big " ▁mak ers ▁producing ▁one ▁or ▁a ▁few ▁vel om ob iles ▁per ▁week . ▁ ▁Vel om ob iles ▁use ▁some ▁standard ▁b icy cle ▁parts , ▁but ▁also ▁many ▁parts ▁specific ▁to ▁vel om ob iles , ▁and ▁thus ▁made ▁in ▁low ▁volume . ▁ ▁The ▁use ▁of ▁" more ▁parts " ▁( e . g ., ▁ 3 ▁whe