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Fuel Requirements Based on Engine Type
As you can see in the tables below, we verified each engine type (both gasoline and diesel) and established what kind of fuel is best. For the gasoline engines, the results are broadly similar. The diesel engines do have a slight difference between the Duramax and Detroit engines.
Gasoline Engines
| Engine | Production | Type Of Gasoline |
| 400 cu in (6.6 L) V8 | 2021-present (L8T) | 87-octane regular, unleaded gasoline |
| 263 cu in (4.3 L) V6 | 2018-present (LV1) | 87-octane regular, unleaded gasoline |
| 364 cu in (6.0 L) V8 | 2003-2008 (LQ4), 2010-2020 (L96) 2018-2020 (LC8) | 87-octane regular, unleaded gasoline |
| 293 cu in (4.8 L) V8 | 2003-2007 (LR4), 2008-2009 (LY2), 2010-2017 (L20) | 87-octane regular, unleaded gasoline |
| 325 cu in (5.3 L) V8 | 2003-2007 (LM7), 2008-2014 (LMF) | 87-octane regular, unleaded gasoline |
| 496 cu in (8.1 L) V8 | 2001-2002 (L18) | 87-octane regular, unleaded gasoline |
| 262 cu in (4.3 L) V6 | 1996-2002 (L35), 2003-2014 (LU3) | 87-octane regular, unleaded gasoline |
| 305 cu in (5.0 L) V8 | 1996-2002 (L30) | 87-octane regular, unleaded gasoline |
| 350 cu in (5.7 L) V8 | 1996-2002 (L31) | 87-octane regular, unleaded gasoline |
| 454 cu in (7.4 L) V8 | 1996-2000 (L29) | 87-octane regular, unleaded gasoline |
Diesel Engines
| Engine | Production | Type Of Diesel |
| 2.8 L Duramax I4 turbodiesel | 2017-present (LWN) | Ultra Low Sulfur Diesel |
| 6.6 L Duramax V8 turbodiesel | 2006-2010 (LLY) 2011-2016 (LLM) | Ultra Low Sulfur Diesel |
| 6.5 L Detroit V8 turbodiesel | 1996-2002 | Originally Low Sulfur Diesel, but Ultra Low Sulfur Diesel can be used |
What Type of Gasoline Can A Chevy Express Take?
Reformulated Gasoline
Gasoline/Oxygenated Blends or E-85
Furthermore, we need to discuss the use of oxygenated blends of gasoline. Oxygenated blends of gasoline typically contain ethanol or methanol. Both additives are bio-sources of fuel and make gasoline burn cleaner. However, the use of methanol or ethanol is strictly regulated in the Chevy Express.
First, it´s good to know that methanol should never be used in any model year of the Chevy Express. Methanol is a very corrosive substance that will damage the fuel system and the engine’s internals.
Chevy Express that aren´t flex-fuel and made in 2011 or before can take gasoline with a maximum percentage of 10% ethanol (also referred to as E10). Chevy Express made from 2012 onwards that aren´t flex-fuel can take gasoline with a maximum percentage of 15% ethanol (also referred to as E15).
Flex-Fuel
Not all Chevy Express are flex-fuel ready. Flex-fuel (also referred to as E85) is a mixture of 51-83% ethanol and 17-49% gasoline. Flex-fuel vehicles can therefore take E10, E15, E30, E50, and E85. However, you need to know precisely what engines and model years can possibly take flex-fuel. Here´s a list:
- 2007 – 2015 Chevy Express with a 5.3L engine
- 2010 – 2013 Chevy Express with a 4.8L engine
- 2010 – 2020 Chevy Express with a 6.0L engine
However, this doesn´t mean that all Chevy Express with these engines can take flex-fuel. To identify whether or not your Express can take flex-fuel, you´ll need to see if it has a yellow fuel cap. If this is the case, flex-fuel can be used. Furthermore, you can also look for badges and markings around the car, as seen in the image below.
If you do decide to use flex-fuel in a flex-fuel ready Express, there are some guidelines you´ll need to be aware of. These are the same for all Express that can take this type of gasoline. Not following these guidelines will result in engine damage.
It is best not to alternate repeatedly between gasoline and E85. If you do switch fuels, it is recommended that you add as much fuel as possible — do not add less than 11 L (3 gal) when refueling. You should drive the vehicle immediately after refueling for at least 11 km (7 mi) to allow the vehicle to adapt to the change in ethanol concentration.
Chevy Express owners´ manual
Addition of Cleaning Agents
If TOP TIER gasoline is unavailable in your region, Chevy recommends that you add ACDelco Fuel.
System Treatment Plus−Gasoline to the vehicle’s gasoline fuel tank at every oil change or 9,000 miles (15,000 kilometers), whichever occurs first. ACDelco is a Chevy-approved fuel treatment that you can buy at a Chevy dealer or online.
What If The Engine Makes A Knocking Noise?
Please remember that soft knocking noise is a normal occurrence from time to time, especially if the vehicle is carrying a heavy load, towing, or driving uphill. However, continuing to drive with a loud knocking noise will result in irreparable damage that is not covered by any warranty.
What’s The Gas Mileage Of The Chevy Express?
One thing the Chevy Express will never be known for is its great gas mileage. Being a heavy van, the Express rarely achieves mileage above 15 MPG. In the table below, we´ve outlined the different engines that have been used with the Express, together with the combined MPG for each engine.
| Engine | Combined MPG |
| 2.8L Diesel | 17 |
| 4.3L V6 | 16 |
| 4.8L Flex-fuel | 15.5 |
| 4.8L V8 | 15 |
| 5.0L V8 | 14.5 |
| 5.3L V8 | 13 |
| 5.7L V8 | 11.5 |
| 6.0L V8 Flex-fuel | 11.5 |
| 6.0L V8 | 14.5 |
| 6.5L Diesel | 11 |
| 6.6L V8 | 14 |
| 6.6L Diesel | 16 |
What Is The Tank Size Of Chevy Express?
2021 – Present
| Type | Quantity | Model Type |
| Standard Tank | 31.0 U.S. gallons (117.3 L) | Passenger and Cargo |
| Standard Tank | 32.0 U.S. gallons (121.7 L) | Cab and Chassis |
| Optional Tank* | 57.0 U.S. gallons (215.7 L) | Cab and Chassis |
2003 – 2020
| Type | Quantity | Model Type |
| Standard Tank | 31.0 U.S. gallons (117.3 L) | Passenger and Cargo |
| Standard Tank | 33.0 U.S. gallons (124.9 L) | Cab and Chassis |
| Optional Tank* | 57.0 U.S. gallons (215.7 L) | Cab and Chassis |
1996 – 2002
| Type | Quantity | Model Type |
| Standard Tank | 31.0 U.S. gallons (117.3 L) | Passenger and Cargo |
| Standard Tank | 35.0 U.S. gallons (132.5 L) | Cab and Chassis |
| Optional Tank* | 55.0 U.S. gallons (208.1 L) | Cab and Chassis |
Closing Thoughts
In this article, we delved into the fuel requirements of the Chevy Express, examining all models from 1996 to the present day. To recap:
Chevy Express vehicles equipped with a gasoline engine, spanning all models from 1996 to today, require regular unleaded gasoline with a minimum octane rating of 87. For those fitted with a Duramax diesel engine, the necessity is ultra-low sulfur diesel; using low sulfur diesel is not advised.
Understanding the right type of fuel to use is pivotal for optimizing your vehicle’s performance. We hope this discussion has equipped you with the knowledge you need to fuel your Chevy Express appropriately, taking into consideration its fuel tank capacity and gas mileage. Thank you for reading!
Sources
Hi! My name is Stefan; I’m the owner and lead writer at TheDriverAdviser.com.
I’m an active writer on this blog myself, as well as a novice car mechanic. For the really technical stuff, I find writers with experience as a mechanic or who have studied mechanical engineering.
Read more about our fantastic team on our about page!