If your looking for a reliable and comfortable truck I would suggest a RAM, I personally own one and it has never let me down in the many years I have been driving.
The best way to find out the gas mileage on your diesel truck would be to go to the popularmechanics.com website. I don't know which year, make or model this particular truck is therefore the mileage would depend.
The F-250 and larger trucks can have diesel engines in them.
The best dually diesel pickup truck would be Chevy or GMC 3500 with Duramax and Allison transmission.
The Allison 1000 which is mated with the Duramax diesel
The top makes for Diesel trucks are Ford, Dodge, and Chevrolet. The best selling Diesel seems to be the Ford F Series. The Duramax engine seems to get very good reviews. The Dodge seems to have more problems with it's engine.
You can find models of Dodge Diesel Trucks by looking at a Model Shop, for example in the UK there is a shop called Modelzone, which sells models including model Dodge diesel trucks. You can also check the internet and sites like Amazon who sell models, and the models they sell might include a Dodge Diesel Truck.
It depends where one looks but a frequently recommended truck for diesel truck pulls is the Ford diesel truck but does cost nearly $60,000. Also recommended are the GMC diesel truck and the Dodge diesel truck.
Dodge. Straight up.
The best all around truck is the Ford Powerstroke, lots of power, handles good and has good gas milage for a diesel.
Amsoil synthetic oil seems to be your best bet for oil for your diesel truck. It helps to prevent oil from becoming foamy and it works in even very hot environments.
Considering that a diesel pickup truck can't use gas I would say that there aren't any diesel trucks that get good gas mileage. If you were wondering which diesel truck gets the highest miles per gallon then I would say you should look at the Dodge Cummins diesel.
The advantage of a diesel truck is that diesel burns more efficiently than regular gasoline. However, parts and service for a diesel truck are sometimes higher.