Tell us what it is getting for mileage, it may be all that is expected. Need more info like present mileage, gear ratio, 2 or 4 wheel drive, aftermarket additions, etc.
the gas lines may need to be cleaned. the airfilter may need to be replaced
No, that is pretty poor mileage.
25cc 1per liter how to km?
50 liter per kilometers
being a 454 it doesn'y get any kind of fuel mileage
~11 km/liter
one mile
This equates to about 9 (8.996) km per liter.
About 15mpg
400000
Not with the technology as it stands, but advances are being made all the time. There are already motorcycles capable of 120mpg(200km per gallon)
The estimated gas mileage for a 2002 GMC Envoy with a 4.2 liter, V6 engine is approximately 20 miles per gallon when driving on the highway. For city driving, the approximate gas mileage is 14 miles per gallon.