2027 Silverado Fuel Costs Compared: Duramax vs. the New V8s Over 50,000 Miles

The 2027 Chevrolet Silverado 1500 introduces two new V8 engines alongside the updated 3.0L Duramax diesel. With the latest fuel economy figures now available, we wanted to see how much each engine would actually cost to fuel over 50,000 miles.

The results might surprise buyers considering the Duramax specifically for its fuel economy.

Despite achieving considerably better MPG ratings than either gasoline V8, the diesel isn't always the least expensive engine to operate when comparing fuel costs alone.

Using current fuel prices in Salt Lake City, Utah, the new 5.7L V8 actually costs slightly less to fuel than the 3.0L Duramax in comparable standard configurations.

However, when comparing the more expensive 6.6L V8 against the Duramax, the diesel has a noticeable advantage.

2027 Silverado Fuel Economy Ratings

The 2027 Silverado offers a new 5.7L V8, a larger 6.6L V8 and the updated 3.0L Duramax diesel. Chevrolet will also offer an enhanced 2.7L TurboMax, although its 2027 fuel economy figures have not yet been released.

Here are the available 2027 ratings.

The diesel continues to hold a substantial fuel economy advantage. Its 24-mpg combined rating in 2WD configuration is seven mpg higher than the equivalent 5.7L V8.

The gap between the Duramax and 6.6L V8 is even larger.

But achieving better fuel economy doesn't always mean spending less money at the pump.

Current Fuel Prices in Salt Lake City

For this comparison, we're using AAA's average fuel prices for the Salt Lake City metropolitan area as of November 5, 2026.

Fuel selection is important because the new Silverado engines don't all use the same fuel.

The 5.7L V8 uses regular 87-octane gasoline, while GM recommends premium gasoline with an octane rating of 91 or higher for the new 6.6L V8.

The 6.6L can operate on 87-octane gasoline when premium is unavailable, although GM warns that doing so will reduce performance and drivability.

The 3.0L Duramax requires diesel fuel.

At the time of this comparison, diesel costs approximately $1.98 more per gallon than regular gasoline in Salt Lake City.

That difference has a substantial effect on operating costs.

How Much Does Each 2027 Silverado Cost to Fuel Over 50,000 Miles?

To keep the comparison consistent, we're using each truck's published combined fuel economy rating.

We divided 50,000 miles by the combined MPG rating to calculate the amount of fuel consumed, then multiplied that amount by the appropriate fuel price.

The numbers assume fuel prices and average fuel economy remain constant throughout all 50,000 miles.

2027 Silverado 50,000-Mile Fuel Cost Comparison

Calculated from AAA Salt Lake City metropolitan fuel prices on November 5, 2026. Costs are rounded to the nearest dollar. Combined MPG figures are based on published 2027 ratings, including GM-supplied information and available EPA-certified window stickers.

The 5.7L V8 Costs Less to Fuel Than the Duramax

Looking at standard 2WD configurations, the 5.7L V8 costs approximately $13,011 in gasoline over 50,000 miles.

The Duramax, despite achieving 24 mpg combined compared with the V8's 17 mpg, costs approximately $13,341 in diesel.

That's a difference of about $330 in favor of the gasoline V8.

The same pattern appears in the standard 4WD configurations.

The 5.7L V8 consumes approximately $13,824 in gasoline, while the 3.0L Duramax consumes approximately $14,554 in diesel.

Here, the V8 saves about $730.

The explanation is relatively simple. The diesel uses considerably less fuel, but each gallon currently costs substantially more.

Over 50,000 miles, the standard 4WD Duramax would consume approximately 2,273 gallons of diesel, compared with 3,125 gallons of gasoline for the 5.7L V8.

That means the Duramax would use approximately 852 fewer gallons.

However, at current Salt Lake City prices, that fuel economy advantage isn't enough to overcome the higher cost of diesel.

The Duramax Has a Major Advantage in the ZR2

The results change when comparing the ZR2.

For 2027, the Silverado ZR2 is available with either the 3.0L Duramax or the new 6.6L V8.

The Duramax ZR2 is rated at 21 mpg combined, while the 6.6L V8 ZR2 is rated at 14 mpg.

Over 50,000 miles, the diesel would cost approximately $15,247 in fuel.

The gasoline-powered ZR2 would cost approximately $17,770 using GM's recommended premium gasoline.

That's a fuel savings of approximately $2,523 for the Duramax.

The 6.6L V8 consumes more fuel and uses more expensive premium gasoline, giving the diesel a financial advantage despite diesel's higher price per gallon.

The Duramax also has a smaller advantage against the 5.7L V8 in the mud-terrain tire configurations.

The 3.0L Duramax 4WD with mud-terrain tires costs approximately $15,247 over 50,000 miles, compared with $15,799 for the similarly equipped 5.7L V8.

That's approximately $552 in fuel savings for the diesel.

What Would Diesel Need to Cost to Beat the 5.7L V8?

With fuel prices constantly changing, the comparison won't always favor the same engine.

Using the current regular gasoline price of $4.4237 per gallon, the break-even diesel price for the standard 2WD Silverado is approximately $6.25 per gallon.

Below that price, the 2WD Duramax would cost less to fuel than the 5.7L V8.

For standard 4WD models, diesel would need to fall to approximately $6.08 per gallon to match the gasoline engine's fuel cost.

The current Salt Lake City diesel average of $6.4037 is above both break-even points.

These thresholds will move whenever gasoline prices change.

Does the Duramax Still Make Financial Sense?

Fuel expenses are only one part of vehicle ownership.

The purchase price, maintenance requirements, diesel exhaust fluid, insurance, depreciation and potential repairs will all influence total ownership costs.

We're intentionally leaving those expenses out of this comparison.

A driver covering 50,000 miles under these assumptions would spend approximately $13,341 fueling a 2WD Duramax, versus $13,011 for the new 5.7L V8.

That's a relatively small difference spread across 50,000 miles.

For buyers considering a standard 4WD truck, the difference is approximately $730 in favor of the 5.7L V8.

Neither amount is especially large when spread over several years of truck ownership.

However, the ZR2 comparison shows a more meaningful advantage for the diesel, saving more than $2,500 in fuel expenses over the same mileage.

Buyers should also consider how they'll use their trucks.

EPA combined fuel economy ratings represent standardized driving conditions. Highway driving, towing, payload, tire choices and driving habits will affect actual consumption.

This comparison should not be interpreted as a prediction of fuel expenses while towing. The published combined ratings don't represent towing fuel economy.

Fuel Economy Doesn't Tell the Entire Story

The 3.0L Duramax remains the most fuel-efficient engine in the 2027 Silverado lineup among configurations with published ratings.

But with diesel selling for nearly $2 more per gallon than regular gasoline in Salt Lake City, its fuel economy advantage doesn't always result in lower fuel bills.

The 5.7L V8 currently has a small fuel-cost advantage in standard configurations, while the Duramax costs less to fuel in the compared ZR2 and mud-terrain configurations.

The biggest difference appears between the Duramax ZR2 and the premium-fuel 6.6L V8 ZR2.

Fuel prices could easily change these results. For now, the comparison demonstrates why looking only at MPG ratings doesn't provide a complete picture of what owners will actually spend at the pump.

Sources: AAA Gas Prices, Salt Lake City metropolitan averages dated November 5, 2026; General Motors 2027 Silverado 1500 owner’s manual fuel recommendations, The Fast Lane Truck and GM-Trucks. com