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The Types Of Gas A Chevy Blazer Uses (All Generations)

The Types Of Gas A Chevy Blazer Uses (All Generations)

On this blog, we carry out a lot of research and analysis on the specific questions you have, no matter how simple or technical they get. Today we are looking at the Chevy Blazer and all of its generations. We will look at the fuel requirements for every model year and engine. Here’s a quick answer before we go into details.

Chevy Blazers manufactured from 2019 onwards that have a 2.0L, 2.5L or 3.6L engine take regular, unleaded gasoline with an octane rating of 87.

Chevy S-10 Blazers manufactured between 1983 – 2005 take regular, unleaded gasoline with an octane rating of 87. The only exception is the 4.3L V6 (1983 – 1994) which takes premium gasoline with an octane rating of 91.

Chevy K5 Blazers manufactured between 1969 – 1994 take with an inline-6 engine take regular unleaded gasoline with an octane rating of 87, whereas the V8 engines take premium gasoline with an octane rating of 93.

This was just the tip of the iceberg. Below, we’ll explain in detail what kind of gasoline is required for each model year and each engine type of the Chevy Blazer. Furthermore, we’ll look at ethanol levels, whether the Blazer can take FlexFuel, and many more questions. Read on!

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Infographic explaing the different fuel types for a chevrolet blazer.

What Kind Of Gas Does A Chevy Blazer Take?

First of all, we have to discuss the kind of gas Chevy has recommended throughout the model years. Below, you’ll find a detailed overview of every generation of the Blazer.

Chevy Blazer Crossover (2019-Present)

red 2023 Chevrolet Blazer RS parked on the side of the street

The Chevy Blazer was re-introduced in 2019 as a crossover. This time around, Chevy put three different engines in the Blazer: a 2.5 inline-4, a 3.6L V6, and a 2.0L turbocharged inline-4. All three of these engines take regular, unleaded gasoline with an octane rating of 87.

EngineFuel Requirement
2.5L Inline-4 Ecotec LCVRegular 87 Octane
3.6L V6 LGXRegular 87 Octane
2.0L turbocharged inline-4 LSYRegular 87 Octane
87 octane, 89 octane and 91 octane fuel levels explained

Chevy (S-10) Blazer (Second Generation, 1995-2005)

blue 2005 Chevy Blazer parked in parking lot

The second generation of the Chevy S-10 Blazer only had a 4.3L V6 in terms of engine options. Once again, Chevy recommends 87-octane gasoline for this engine.

EngineFuel Requirement
4.3L Vortec V6Regular 87 Octane

Chevy (S-10) Blazer (First Generation, 1983-1994)

1994 white chevy blazer parked in driveway

Now coming to the midsize Blazer, also known as the S10 Blazer. The first generation debuted in 1982, with the S-10 platform to be sold in 1983. This segment was introduced to compete with the competitors who were selling these compact SUVs like hotcakes.

The 4.3L (code W) engine uses 91 octane or higher unleaded gasoline. For all the remaining engine options, only use 87 octane or higher.  The only exception to this is when you are towing or have a heavy payload. In these cases, it is preferred to have high-octane (91 or higher) gasoline instead of the usual 87.

EngineFuel Requirement
1.9L (1983-1985)Regular 87 Octane
2.0L OHV inline-4 (1983-1985)Regular 87 Octane
2.8L V6Regular 87 Octane
Fuel-injected 2.5L (Iron Duke) 1985-1989Regular 87 Octane
4.3L V6Premium 91 Octane
2.8L V6 (1989-1990)Regular 87 Octane

Chevy K5 Blazer (Third Generation, 1992-1994)

white blue 1992 Chevy K5 blazer parked in the woods

Before the S-10 Blazer was introduced, the Blazer was sold as the so-called K5 Blazer. The third generation of this Blazer was equipped with a 5.7L V8 which took 91-octane at the minimum and had 93-octane preferred for optimum performance and longevity. Furthermore, this generation was also available with a 6.2L Detroit Diesel turbocharged V8 which took ultra-low sulfur diesel number 2.

EngineFuel Requirement
5.7L 350 CID V8 LO5Premium 91 octane required, 93 octane preferred
6.2L Detroit Diesel Turbocharged V8Ultra-Low Sulfur Diesel No. 2

Chevy K5 Blazer (Second Generation, 1973-1991)

white brown 1979 chevy k5 blazer parked on the side of the road

The second generation had a bunch of engine options, all of them between 4.1 – 6.2L. For the inline-6 engines, 87-octane is recommended, whereas the V8s take 93-octane, preferably. Once again, the 6.2 V8 Diesel takes ULSD 2.

EngineFuel Requirement
4.1 Inline-6Regular 87 Octane
4.8 Inline-6Regular 87 Octane
5.0 V8Premium 91 octane required, premium 93 preferred
5.7 V8Premium 91 octane required, premium 93 preferred
6.6 V8Premium 91 octane required, premium 93 preferred
6.2L Detroit Diesel LH6 V8 Ultra-Low Sulfur Diesel No. 2

Chevy K5 Blazer (First Generation, 1969-1972)

red 1971 chevy k5 blazer parked on the side of the road

For the first generation of the K5 Blazer, all six-cylinder engines use regular gas. V8s require premium gas with an octane rating of 93 or higher.

EngineFuel Requirement
4.1 L22 Inline-6Regular 87 Octane
4.8 L25 Inline-6Regular 87 Octane
5.0 V8Premium 93 Octane
5.8 LS9 V8Premium 93 Octane

What Types Of Gasoline Can And Can’t Be Used?

Besides octane ratings, there are many more aspects that come into play when picking the right type of fuel for the Chevy Blazer. Below, we’ll discuss the options you have.

Reformulated Gasoline

It’s one of the newer types of gasoline available in the market, specifically designed to have fewer carbon emissions compared to conventional gasoline. Although it’s not on the list of recommended fuels, you can, however, use RFG — it’s safe and wouldn’t cause damage to the engine.

This fuel is useful in areas that have strict emission requirements. However, people in regions with extreme pollution should have reformulated gasoline regardless – as it would help the environment by exposing it to fewer emissions, less smog, and, most importantly, we get a better air quality index.

Even though the owner’s manuals of the different Chevy Blazers don’t have anything specified about reformulated gasoline, we know that Chevy Blazers are compatible with reformulated gasoline because it’s mandatory in certain regions of the United States.

Gasoline/Oxygenated Blends

Oxygenated gasoline blends are types of gasoline blended with a certain amount of ethanol or methanol. These chemicals are mainly helpful during winter when temperatures drop lower and lower. This provides a more difficult starting point for the engine. Ethanol and methanol help the engine start more quickly.

Ethanol levels for cars explained, E10, E15 and E85

However, you can’t get just ethanol or methanol whenever you please. These chemicals are pretty dangerous for the engine and the fuel system, and using them should be done by following these rules:

  • No generation of the Chevy Blazer is compatible with methanol, therefore, do not use any percentage of methanol in Chevy Blazers that have been made in the past or that are currently produced.
  • Chevy Blazer, made before 2005, can take gasoline with a maximum percentage of 10% ethanol. Chevy Blazer, made from 2019 onwards, can take gasoline with a maximum of 15% ethanol.

E85 / FlexFuel

No generation of the Chevy Blazer is compatible with FlexFuel. Therefore, It’s advised against using the E85. If you do so, you will be damaging your engine components, and any form of warranty does not cover this.

Gasoline With Added Materials

Another gasoline-specific topic we will talk about is the use of additives that need to be mixed into your fuel. These additives are widely available on the market these days. Supposedly they do a whole range of different things, such as:

  • Boost the octane level in your fuel, thereby giving it better performance.
  • Help the engine clean itself more effectively.

However, it’s good to know that Chevy strongly advises against using additives in your Blazer. This is because these additives can contain materials such as silicon or metallics that will seriously damage the engine and the fuel system, affecting how long your Chevy will last.

Therefore, it’s recommended that you buy fuel that already has all the proper additives mixed into it. This kind of fuel can be purchased at certified TOP TIER gasoline retailers. These retailers sell gasoline that will provide the optimal performance for your engine and clean it as well as possible without damaging it. You can find a retailer at

If TOP TIER detergent gasoline is not available in your region, you can put an additive that is endorsed and sold by Chevy themselves. This additive is called ACDelco Fuel System Treatment Plus-Gasoline and can be found online or at your local GM or Chevy dealer.


Some Chevy Blazers are equipped with a Detroit Diesel V8, which takes ultra-low sulfur diesel no.2. There’s very little else to say except for following this particular recommendation.


For everyday driving where diesel might be sitting in the gas tank for about 4-6 weeks, it is advised to use less than 5% by volume (B5).

Biodiesel, on the other hand, has a higher percentage than this. However, if the fuel does not remain in the tank for more than four weeks and you fill it with fresh diesel, you may use biodiesel more than 5% by volume – up to 20%.

To keep the internals clean, Chevy recommends using TOP TIER Diesel Fuel to keep the carbon debris level as low as possible. If you can’t find this in your region, you can use ACDelco Diesel Fuel Conditioner instead. These additives enhance the diesel’s performance by making it more stable.

What If I Hear A Knocking Noise From The Engine After Refilling

Furthermore, using fuels with an octane rating lower than recommended will result in severe damage to the engine, which is indicated by a symptom referred to as engine knock.

Engine knock means that the fuel can’t be adequately burned, resulting in a heavy knocking sound of the engine. A slight knocking sound is never a problem, but heavy knocking should be dealt with immediately.

Please stop the vehicle and contact your dealers if this heavy knocking occurs. You’re likely using fuel with a lower-than-recommended octane rating. The car needs to be drained, the fuel filter will need to be replaced, and the battery will need to be disconnected and reconnected to reset the car’s memory.

Does the Chevy Blazer Have Good Gas Mileage?

Of course, we can’t discuss all of this without outlining the gas mileage of each generation as well. Once again, you’ll find a detailed overview below.

Chevy Blazer Crossover (2019-Present)

2.5L Inline-4 Ecotec LCV
2.5L Inline-4 Ecotec LCV
EngineCity MPGHighway MPG
2.5L Inline-4 Ecotec LCV2529
3.6L V6 LGX2227
2.0L turbocharged inline-4 LSY2427

Chevy (S-10) Blazer (Second Generation, 1995-2005)

4.3L Vortec V6
4.3L Vortec V6
EngineCity MPGHighway MPG
4.3L Vortec V61113

Chevy (S-10) Blazer (First Generation, 1983-1994)

Fuel-injected 2.5L inline-4 (Iron Duke) 1985-1989
Fuel-injected 2.5L inline-4 (Iron Duke)
EngineCity MPGHighway MPG
1.9L (1983-1985)2328
2.0L OHV inline-4 (1983-1985)2225
2.8L V6 (1989-1990)1819
Fuel-injected 2.5L inline-4 (Iron Duke) 1985-19892125
4.3L V61618

Chevy K5 Blazer (Third Generation, 1992-1994)

Detroit Diesel V8 outside of vehicle
Detroit Diesel V8
EngineCity MPGHighway MPG
5.7L V81115
6.2L Detroit Diesel Turbocharged V889

Chevy K5 Blazer (Second Generation, 1973-1991)

Chevy 6.6 V8
Chevy 6.6 V8
EngineCity MPGHighway MPG
4.1 Inline-61517
4.8 Inline-61516
5.0 / 5.7 / 6.6 V89-1113-15
6.2L Detroit Diesel LH6 V8 1416

Chevy K5 Blazer (First Generation, 1969-1972)

5.8 LS9 V8
5.8 LS9 V8
EngineCity MPGHighway MPG
4.1 L22 Inline-61517
4.8 L25 Inline-61413
5.0 V81113
5.8 LS9 V81014

What’s The Gas Tank Size Of A Chevy Blazer?

Finally, we’ve taken the liberty to outline the gas tank size of each generation as well.

Chevy Blazer Crossover

GenerationTank Size
First Generation (2019 – Present)Front Wheel Drive – 19.4 gallons
All Wheel Drive – 21.7 gallons

Chevy S-10 Blazer

GenerationTank Size
First Generation (1983 – 1994)20 gallons
Second Generation (1995 – 2005)20 gallons

Chevy K5 Blazer

GenerationTank Size
First Generation (1969 – 1972)Standard – 25 gallons
Station Wagon – 22 gallons
Second Generation (1973 – 1991)Standard – Gas – 25 gallons
Standard – Diesel – 27 gallons
NK7 Option – Gas – 31 gallons
NK7 Option – Diesel – 32 gallons
NE2 Option – Gas – 40 gallons
NE2 Option – Diesel – 41 gallons
Third Generation (1992 – 1994 ) 20 gallons

Closing Thoughts

Through this article, we have explored the fuel requirements across different generations and engine types of the Chevy Blazer. Here’s a quick recap:

  • 2019 onwards models with 2.0L, 2.5L, or 3.6L engines, as well as the S-10 Blazers (1983-2005) mainly require regular, unleaded gasoline with an 87 octane rating, albeit with some exceptions.
  • Chevy K5 Blazers between 1969 and 1994 have varied requirements depending on the engine type, ranging from an 87 to a 93 octane rating.

For a deeper understanding of each engine type’s specific needs, including ethanol levels and FlexFuel compatibility, refer back to the detailed sections above. We trust you now have a comprehensive view of the fuel specifications for the Chevy Blazer across different eras.


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