Www.utoGuide.com has a list of the top ten most fuel efficient pickup trucks for 2013. Www.shopautoweek.com also has a list of its top four most fuel efficient pickup trucks.
A very straightforward guide to the best fuel efficient trucks can be located at http://www.autoguide.com/auto-news/2012/02/top-10-most-fuel-efficient-pickup-trucks.html. It gives details on the best MPG trucks of 2013.
There hasn't really been a brand of semi trucks recognized as the most fuel efficient. Since they run on diesel a more efficient fuel, semi trucks already are more fuel efficient than cars in terms of size and power.
Hybrid trucks are definitely more fuel efficient than conventional gasoline powered trucks. Hybrid model trucks generally have up to 25% better fuel economy than their gasoline alternatives.
US News has the ranking for the best efficient cars. You can read them at http://usnews.rankingsandreviews.com/cars-trucks/rankings/Affordable-Small-Cars/
When trying to find a comprehensive review of vehicle specifications like fuel efficiency, it is best to seek out individual reviewers. In regards to trucks, a great site is Fuel Economy, which gauges miles per gallon based on multiple measures of truck usage (i.e. city vs. highway).
The fuel efficiency of International's Navistar truck line depends upon how you set the electronics and how the driver operates it. The most efficient ones are the Paystar line, which are also the smallest. International makes a full range of over the road trucks.
Most larger trucks burn diesel fuel.
The most fuel efficient GMC Truck you can get it the GMC Banarge, it can come with a small 1.8ltr Diesel Engine offering upto 25Mpg, tho this truck is rather slow it can be great for starter businesses to save on fuel costs
Many SUV's are not fuel efficient.
There are several places you can look online to find a list of the most fuel efficient cars. Check FuelEconomy.gov, they have a pretty extensive list. CNN recently did a story on the eight most fuel efficient cars. Check out their report.
Yes even the trucks are more suitable for the earth than conventional fuel driven cars. The most fuel efficient automobiles are hybrids because they get better mileage and do not require as much gas.
Many truckers believe the Cascadia gets the best mpg. I hear truckers say they get about 7 mpg on the open road with them.http://www.freightlinertrucks.com/trucks/find-by-model/cascadia/default.aspx