A diesel truck makes more torque, tows heavy trailers more easily and usually returns better fuel economy than a comparable gas truck, and heavy-duty diesels are built to last a long time. A gas truck costs less to buy, costs less to maintain, warms up and starts more easily in cold weather, and has no diesel exhaust fluid or diesel particulate filter to look after. The right choice depends mostly on how much and how often you tow.
Diesel vs gas truck at a glance
| Diesel | Gas | |
|---|---|---|
| Torque and towing | Much more low-speed torque; better for heavy, frequent towing | Fine for light or occasional towing |
| Fuel economy | Usually better, especially when loaded | Usually lower |
| Purchase price | Diesel engines are an expensive option | Lower |
| Maintenance | Larger oil capacity, fuel filters, water separator, and on newer trucks DEF and particulate filter | Simpler and cheaper |
| Longevity | Heavy-duty diesels are built for long service | Modern gas V8s also last long with care |
| Cold weather | Needs grid heaters or glow plugs; fuel can gel without winter blends | Starts easily |
When a diesel makes sense
- You tow heavy trailers often, especially over long distances or grades.
- You drive high mileage, where the fuel economy advantage adds up.
- You keep trucks a long time.
When a gas truck makes sense
- You tow lightly or occasionally.
- Most driving is short trips, which do not suit modern diesel emissions systems.
- You want lower purchase and running costs.
- You live where winters are very cold and do not want to manage block heaters and winter fuel.
Running costs to consider
- Fuel price: diesel and gasoline prices vary by region and season, which changes how quickly better economy pays back.
- Diesel exhaust fluid: newer diesels use DEF, which is topped up between oil changes.
- Service: diesel oil changes and fuel filters cost more than routine service on a gas truck.
- Repairs: diesel injection and turbo parts are expensive, so maintenance matters; see turbo failure symptoms and CP3 pump.
Engines we carry for both
For diesel Ram trucks we carry D&J 5.9 and 6.7 Cummins short blocks, long blocks and complete packages on our Cummins engines page; compare diesels in Cummins vs Duramax vs Powerstroke and read 6.7 Cummins specs. For gas trucks we carry 5.7 Hemi, Chevy 5.3 and 6.0 Vortec and Ford 5.4 engines; see 5.7 Hemi specs, LS engine specs and our engines by engine code. Ram history: Ram generations.
More guides: how long diesel engines last.
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