This blog is the culmination of an enormous amount of effort that we put into research for accurate assessment and answers for all fuel-related questions related to your vehicle. This blog will answer fuel requirement questions related to all generations and engine types of Chevy Silverado. All the answers in this blog were gathered by going through the incredibly detailed manufacturer’s guides and suggestions on fuel requirements. Before you dive deeper into the details, here is a quick summary:
Gasoline with a minimum of 87 octane rating is required for all generations and engine types of Chevy Silverado 1500/2500/3500 except the 6.2L V8 engines. 6.2L V8 engines were introduced in the 4th generation of Silverados released in 2019. For 6.2L V8 engines, the recommended gasoline is 93 octane premium unleaded gasoline.
The above summary is just the tip of the iceberg. Now, we will dive deeper into every engine and the type of gas you can or cannot use with the engine. Grab a cup of coffee and get comfortable. First, we will introduce you to all the engine types and their fuel requirements, and then we will discuss which engines are better and which are worse in different situations. So, without further ado, let’s get started.
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Fuel Requirements Based On Engine Type
Although there are 4 generations of Chevy Silverado, for fuel requirements, we only need to consider the 4th generation 6.2L V8 engine and the Duramax 3.0L Turbo-Diesel Inline- 6 engine on its own. The fuel requirements of all the engines in the first three generations are the same and there’s also a lot of overlap when it comes to transmission issues between generations as well.
The manufacturer recommends the use of TOP TIER Detergent Gasoline. It helps to keep the engine clean and reduce engine deposits. It also helps maintain the optimal performance of vehicles.
2019- Present
All gasoline engine types of the 4th generation, excluding 6.2L V8 engines, should get a minimum of 87 octane gas.
For the 6.2L V8 engines of the 4th generation, the recommended octane level is 93 premium unleaded gasoline, meeting the ASTM specification D4814. It offers the best economy and engine performance. Lower octane gas can be used, but it offers a degraded level of performance and economy. If you put lower octane-rated gasoline in a high compression engine, the gasoline will burn prematurely, and the burn won’t be as smooth as it should be, thus reducing the engine’s performance and causing engine knock.
If the fuel cap on your vehicle does not have a yellow fuel cap or a yellow sticker on the fuel door, then do not use gasoline or ethanol levels greater than 15% in your vehicle.
All Silverado vehicles, regardless of the generation and engine type, all Silverado vehicles do not use gasoline with an octane number less than 87. Using gasoline with an octane number less than 87 will cause engine knocking and lower fuel economy.
Now let’s talk about the fuel requirements of the new and advanced Duramax 3.0L DOHC Turbo Diesel engines released in 2019. The manufacturer recommends using TOP TIER Diesel Fuel that will help keep the diesel engine clean and reduce engine deposits. It will help the vehicle maintain its performance.
1999 to 2019
The first generation of Chevy Silverado was released in 1999, and all subsequent generation and engine models up to the 4th generation have the same fuel requirements. The basis is TOP TIER Detergent Gasoline that will help keep the engine clean, reduce engine deposits, and maintain optimal engine performance.
The recommended fuel for all engine types and generations before 2019 is regular unleaded gasoline with a minimum octane number of 87. If the fuel cap on your vehicle does not have a yellow fuel cap or a yellow sticker on the fuel door, then do not use gasoline or ethanol levels greater than 15% in your vehicle.
Now let’s talk about the Duramax 3.0L DOHC Turbo Diesel engines. The manufacturer recommends the use of TOP TIER Diesel Fuel that will help keep the diesel engine clean and will also reduce engine deposits. It will help the vehicle maintain its performance.
What Types Of Gasoline Can And Can’t Be Used?
In the modern days, we not only have traditional/conventional gasoline and diesel, but we also have many other types of fuel that can be used depending on the engine types, model, and generation. Several of these alternative fuels market themselves as a great alternative to traditional fuel, but the question is, are they really a better alternative? In this section, we will look at how effective or ineffective these modern fuels are when it comes to Chevy Silverado.
Chevy Recommendation
Chevy itself recommends all the owners of Silverado to use the TOP TIER Detergent Gasoline. They do so because this gasoline helps keep the engine clean and reduces engine deposits. This gasoline also helps maintain an optimal level of vehicle performance.
Chevy also recommends the use of gasoline with a minimum octane number of 87 for all generations and engine types except 6.2L V8.
For the 6.2L V8 engine, Chevy recommends gasoline with a recommended octane number of 93. If fuel with a lower octane number is used, it will lead to knocking, and the engine might be damaged with prolonged use.
For all generations of Duramax 3.0L DOHC Turbo Diesel engines, the recommendations of the Chevy are the same. They recommend using TOP TIER Diesel Fuel. Using this fuel will help keep the engine clean and free of fuel deposits. It will also help your vehicle maintain its optimal performance. Chevy also discourages the use of fuel with more than 15 ppm sulfur.
Reformulated Gasoline
Reformulated gasoline is a modern fuel that is available in the market. This fuel is specially designed to have lower carbon emission, and it is extremely useful for areas with strict carbon emission requirements for vehicles.
Although reformulated gasoline is not discussed in any manufacturer’s guides and recommendations, the reformulated gasoline can be used in Chevy Silverado, and other models like the Chevy Cruze and the Chevy Suburnan. RFG is safe and will not cause damage to an engine.
Even if the carbon emissions requirements in your area are not strict, it is still useful to use reformulated gasoline to help the environment with lower carbon emissions that would result in less smog that will lead to a better Air Quality Index.
Gasoline/Oxygenated Blends Or E-85
No fuel with more than 15% ethanol should be used in Chevy Silverado. Even mid-level ethanol blends, 16% to 50% ethanol, should not be used. E-85 or FlexFuel should not be used for all Silverado models that do not have a yellow gas cap or do not have a yellow sticker on the gas lid.
Adding such fuels to the Silverado will lead to damage to the engine and its components. FlexFuel contains 85% ethanol, and although it might run pretty clean in some engines, for Chevy Silverado, it has a corrosive nature. If your vehicle is not designed to handle such fuel, it must not be used under any condition.
The manufacturer’s guide and recommendations specifically discourage the use of such fuels except for vehicles designed to use such fuels.
Silverado models, from any generation, are designed for such fuels, the manufacturer encourages the use of FlexFuel and E-85. Before using these fuels, ensure that they meet the ASTM specification D 5798 or CAN/CGSB.
For areas or times of the year when the temperature goes below 0 ℉ (18 ℃), gasoline should be added to E-85 and FlexFuel. It is also recommended to use regular recommended gasoline in such low temperatures.
Gasoline With Added Materials
Just like the numerous modern fuels that we have in the market, we also have hundreds of additives that are readily available in the market, with effects ranging from increasing the octane number to cleaning the engine’s internal components.
In this section, we will look at those that are beneficial and those that might cause harm.
All additives that include methanol, methylal, ferrocene, and aniline should be avoided at all costs. Such additives can corrode the metallic parts of the fuel system and might even damage plastic and rubber components they come in contact with.
Chevy recommends the use of TOP TIER Detergent gasoline to clean the engine and increase performance and mileage. Chevy also recommends the ACDeco Fuel System Treatment Plus-Gasoline additive to a full tank at every oil change or every 9000 miles, whichever comes first. This additive will help keep your engine fuel deposit-free and keep it running at optimal performance.
Now let’s talk about the additives for Duramax 3.0L DOHC Turbo Diesel engines. As for fuel additives, the manufacturer recommends TOP TIER Detergent Diesel, and if it is not available in your area, then the next best additive is ACDelco Diesel Fuel Conditioner that will help you maintain its optimal performance. The manufacturer does not recommend other aftermarket fuel additives containing alcohols, organo-metallic additives, or water emulsifiers.
In case only low-quality diesel is available to you, Chevy recommends the addition of ACDelco Fuel System Treatment Plus-Diesel which will help clean engine deposits.
Gasoline With MMT
MMT is an acronym for Methylcyclopentadienyl Manganese Tricarbonyl. MMT can severely damage the emission system and can even damage the spark plugs. MMT is a metal additive that is not recommended or endorsed by any manufacturer. The warranty does not cover the damage that is caused by introducing this additive into your engine.
MMT was mostly used in leaded gasoline that helped reduce the knocking sound of the engine. The downside of this additive, along with damage to the engine, was the environmental damage it caused.
Metal additives, nowadays, are only used in race fuels. And due to the environmental damage that leaded fuel causes, it is generally prohibited to add lead to gasoline.
Biodiesel
Chevy does not recommend using diesel blends with more than 20% biodiesel by volume when it comes to biodiesel. And if your vehicle is not driven, often it is recommended to use only a 5% biodiesel blend.
Using fuel that does not meet the set biofuel recommendation can lead to engine power loss, accelerated wear and tear on the engine, general engine damage, and it can even void your warranty.
What If I Hear A Knocking Noise From The Engine After Refilling
If you hear a faint knocking sound from the engine, then everything is normal. If you hear a loud knocking sound, then the most probable culprit is low-quality fuel that has a lower octane rating than recommended.
In case you hear extremely loud knocking sounds from your engine, then you should take your vehicle to an authorized dealership immediately to get your engine properly checked and diagnosed.
- Also read: 8 Common Problems Of A Chevy Silverado 2500/3500 (HD)
- Also read: 15 Common Problems Of A Chevy Silverado 1500
Does the Chevy Silverado Have Good Gas Mileage?
The mileage of Chevy Silverado greatly depends on the type of engine and your choice of 2WD or 4WD. Given below is a table of mileage depending on 2WD or 4WD with respect to engine models:
| Engine | Lowest Combined MPG (2WD, 4WD) | Highest Combined MPG (2WD, 4WD) |
| 2.7L | 20, 19 | 23, 22 |
| 3.0L (Diesel) | 23, 22 | 33, 26 |
| 4.3L | 16, 15, 14 (4WD Trail Boss) | 21, 20, 18 (4WD Trail Boss) |
| 5.3L (6 Speed) | 14, 14, 13 (4WD Trail Boss) | 21, 20, 18 (4WD Trail Boss) |
| 5.3L (6 Speed, Active Fuel Management) | 15, 15, 14 (4WD Trail Boss) | 21, 20, 18 (4WD Trail Boss) |
| 5.3L (8 Speed, Dynamic Fuel Management) | 17, 16 | 23, 22 |
| 5.3L (10 Speed, Dynamic Fuel Management) | 15, 15 | 21, 21 |
| 6.2L | 23, 22 | 33, 26 |
What’s The Gas Tank Size Of A Chevy Silverado?
The gas tank size of a Regular Cab Silverado is 28.3 gal./ 107 liters, while the tank size of both Double Cab and Crew Cab is 24 gal./ 91 liters.
How Much Does It Cost To Fill Up A Chevy Silverado
It will cost an average of $100 to fill up a Regular Cab Silverado, and it will cost an average of $85 to fill up a Double Cab Silverado and Crew Cab Silverado when it comes to gasoline. If we talk about diesel, it will cost $92 and $80, respectively.
Filling up a Chevy Silverado will cost the cheapest in Oklahoma, with $66 for Regular Cab and $57 for Double Cab and Crew Cab when it comes to gasoline. If we talk about diesel, it will cost $82 and $70, respectively.
Filling up a Chevy Silverado will be most expensive in California, with $122 for Regular Cab and $105 for Double Cab and Crew Cab when it comes to gasoline. If we talk about diesel, it will cost $123 and $105, respectively.
Conclusion
In the journey of understanding the intricate details of your Chevy Silverado’s fuel requirements, we’ve discovered that the type of gasoline and its octane rating can make a significant difference in your vehicle’s performance and longevity. These factors can also influence the vehicle’s emission profile, contributing to its environmental footprint.
In our deep dive, we’ve covered everything from the best gas type for each engine to the impact on the Silverado’s performance under various conditions. By now, you should be well-equipped to make informed decisions about the fuel requirements for your Chevy Silverado, whether it’s the 1500, 2500, or 3500 model.
Remember that your Silverado is more than its engine and the fuel it consumes; it’s a sum of meticulously designed parts working in perfect harmony. That includes everything from the 6-lug bolt pattern of the 1500 (or the 8-lug pattern on the larger 2500) to the transmission and everything in between. Plenty of things can go wrong in the Silverado but knowing what you’re up against is half the battle.
Continuing your vehicle’s journey with care and knowledge will ensure its performance and longevity. So, keep learning and happy driving!
Sources
- Chevrolet Silverado 1500 – 2021
- 2021 Chevrolet Silverado 1500 Owner’s Manual
- 2021 Chevrolet Silverado 2500HD/3500HD Owner’s Manual
- 3.0L GMC Duramax Diesel Engine Supplement Owners Manual
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.
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