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Types Of Gas A Ford Bronco Takes (Explained)

Types Of Gas A Ford Bronco Takes (Explained)

In this era of digital information, anyone can get information from many different sources. Therefore, misinformation is getting more and more common. Our team here at “thedriveradviser” is putting in a lot of effort to provide you with accurate, research-based, and official answers. On this blog, we will answer all the fuel-related questions. The main one would be what gas you should and should not be adding to your Ford Bronco.

The Ford Bronco requires regular unleaded gasoline with 87 of octane, while 91 or higher octane is recommended. TOP TIER Detergent Gasoline is the recommended additive. Flex-fuel/E85 is not recommended. Adding so will damage the system. 

This doesn’t tell us the complete story as it is just the summary. To make it clear, we have discussed everything in detail. We have divided this blog into a couple of sections. First, we will look at all the engine options available in Bronco’s lineup across all the generations and see which gas is required for each particular engine option. Furthermore, we will look at all the additives and see which ones you can use and which ones can damage your engine.

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Infographic explaining the different fuel types for a ford bronco

Fuel Requirements Based On Engine Type


Between 1966-1992 five generations of Ford Bronco were developed by Ford company, and the 6th generation came to market in 2021. Engine types for this generation are EcoBoost® 2.3L Ti-VCT GTDI I-4 and 2.7L Ti-VCT GTDI V6.

Ford Bronco operates on regular unleaded gasoline with a minimum pump (R+M)/2 octane rating of 87. The fuel capacity for a 2-door is 16.9 (gal.), and 20.8 (gal.) for a 4-door. EPA Fuel Economy is 26 MPG combined (city/highway), giving 3.8 gal/100mi, which makes 416 miles total range.

For best overall vehicle and engine performance, premium fuel with an octane rating of 91 or higher is recommended by Ford which is a departure from the fuel requirements of other Ford SUVs like the Explorer but in line with vehicles like the Escape’s more recent premium fuel requirements. The performance gained by using premium fuel is most apparent in hot weather and other conditions, towing a trailer, for instance. 

Do not be concerned if the engine sometimes knocks lightly. However, if the engine knocks heavily while using fuel with the recommended octane rating, contact an authorized dealer to prevent any engine damage. Using poor quality fuel also causes engine knock. To avoid any engine damage, make sure only to use the recommended fuel type and additive.

The manufacturer recommends Top Tier detergent gasoline, which is available to help minimize engine deposits and maintain the optimal vehicle and engine performance.

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

Some fuel stations, specifically those in high altitude areas, offer regular unleaded gasoline with an octane rating below 87. Ford advises against using those fuels. These fuels could result in engine damage that the vehicle warranty will not cover. So make sure to have spare fuel when you are traveling up hills.

Using any fuel for which the vehicle was not designed will impair the emission control system, cause loss of vehicle performance, and damage the engine – which may not be covered by the vehicle Warranty.

Do not use

  • Diesel fuel
  • Fuels containing kerosene or paraffin
  • Fuel containing more than 15% ethanol or E85 fuel
  • Fuels containing methanol
  • Fuels containing metallic-based additives, including manganese-based compounds.
  • Fuels containing the octane booster additive, methylcyclopentadienyl manganese tricarbonyl (MMT)
  • Leaded fuel, using leaded fuel is prohibited by law
  • The use of fuels with metallic compounds such as methylcyclopentadienyl manganese tricarbonyl, which is a manganese-based fuel additive, will impair engine performance and affect the emission control system

Reformulated Gasoline

Reformulated gasoline (RFG) is gasoline blended to burn more cleanly than conventional gasoline and reduce smog-forming and toxic pollutants in the air we breathe. The RFG program was mandated by Congress in the 1990 Clean Air Act amendments. The first phase of the RFG program began in 1995, and the second (current) phase began in 2000.

RFG is required in cities with high smog levels and is optional elsewhere. RFG is currently used in 16 states and the District of Columbia. About 25 percent of gasoline sold in the U.S. is reformulated. (Source)

Gasoline/Oxygenated Blends Or E-85

There are many oxygenated blends available in the market. Vehicles produced before 2011 would run fine on ethanol percentages up to 10% by volume. In 2011, the EPA allowed up to 15% ethanol by volume mixed with 85% regular gasoline.

More than 15% ethanol would harm the engine. The warranty does not cover those damages that are done to the engine by adding improper additives. The E85, also known as the flex-fuel, should only be added in vehicles specifically designed to run on flex-fuel. To know for sure whether or not the vehicle in question is flex-fuel appropriate or not, follow the steps below:

  • Look at the gas cap, you will find E85 imprinted on it if it’s made to run flex fuel.
  • If the cap gas, it might be on the back of the gas door.
  • Usually, as a standard, flex-fuel vehicles have yellow gas caps.

When you have made sure that your vehicle is flex-fuel appropriate, you need to make sure you are following the necessary protocols.

  • Do not add less than 3 gallons when you are interchanging fuels.
  • Do not park your vehicle right after a refill, at least drive it for about 8 miles.

Do not add any additives when you are running on flex-fuel. It will do more damage than good. Before adding ethanol to any vehicle, you should first make sure if it is Flex Fuel Vehicle (FFV).

Gasoline With Added Materials

The market is filled with all kinds of additives – and most of them are harmful to your engine. Ford advises using only TOP TIER Detergent Gasoline to help clean your engine’s internals and help keep you up to the mark on emission standards. This specifies additive will help you steer clear of all those harmful additives.

Most of the octane boosters in the market have metals that are going to damage your engine. You are not allowed to mix methanol, MMT, more than 15% ethanol, etc. These additives are only used in race fuels because race engines are not meant to last hundreds of thousands of miles – they only last a couple of races.

Gasoline With MMT

This additive, MMT, stands for Methylcyclopentadienyl Manganese Tricarbonyl that helps increase the octane rating of a poor-quality fuel. This additive is strongly advised against, and you should not be adding this to your gas tank. This additive is not recommended because it damages the emissions control system on top of reducing spark plugs’ life.


This is an additive that can be added not more than 20% by volume along with diesel. It reduces carbon emissions, and it also helps give better mileage. There are no diesel variants for the Ford Bronco in which you can use this additive.

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

A very faint knocking sound from the engine is typical. However, if you have started to hear knocking noises from the engine after refilling, then most probably, the quality of the fuel is the culprit here. If the engine’s octane requirements are not met, and the fuel has less than the minimum required octane, you will experience knocking.

If you hear a very loud knocking sound, you should immediately take your Ford Bronco to the dealership and have it checked. To get rid of the knocking, you can fill the tank with mid-grade or premium gasoline. If you still hear knocking sound after running on mid-grade or premium fuel, then your engine needs service.

Running poor quality fuel or adding non-recommended additives will result in knocking. If the engine gets damaged due to these factors, your warranty may get void.

Does the Ford Bronco Have Good Gas Mileage?

EngineLowest Combined MPGHighest Combined MPG
2.3L Ti-VCT GTDI I-42126
2.7L Ti-VCT GTDI V-62126

What’s The Gas Tank Size Of Ford Bronco?


2-Door16.9 gallons
4-Door20.8 gallons

How Much Does It Cost To Fill Up a Ford Bronco?

There are two different sizes of gas tanks available, So let’s take a 20.8-gallon gas tank as a point of reference. If you happen to be in California, you would be paying the highest price per gallon, which is $4.711, and for a full 20.8 gallons, your total would be approximately $98.

On the other hand, if you live in Oklahoma, you would be paying the least amount per gallon, which is $2.955, and for 20.8 gallons, your total would be approximately $61.

Our research has shown that gas prices are going up steadily. So overall, the price for a full tank, from the smallest size available to the largest one, can be somewhere between $47.59-$91.27, from the cheapest to the most expensive. These prices have been calculated at the time of writing this article.


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