Pickup Trucks 101: 10 Common Fuel Questions

Octane Ratings copy II

By Matthew Barnes

Pickup truck owners can choose from a variety of fuels, each of which works differently in a pickup. Not sure which fuel is best for your truck? Read on for the answers to common questions about fuel.

What Does the Octane Rating Indicate?

A fuel's octane rating measures how much that fuel can be compressed before it auto ignites. Preignition, when gasoline ignites before the spark plug fires, can cause significant damage to an engine. When a truckmaker calls for a certain octane level, that is the level at which the engine will run without preignition issues. Higher-octane gas can withstand preignition at higher pressures, which is why many turbocharged engines require 91-octane fuel. While using a higher-than-recommended octane rating won't hurt an engine, it also usually won't provide any additional benefits for most vehicles. For old or heavily worn engines, or if a pinging sound can be heard from the engine, running higher-octane fuel may extend the life of the engine.

What Octane Rating Should I Use?

Some engines may ping or pre-ignite under heavy loads but run fine otherwise. If this is the case, running higher octane when towing or hauling could be beneficial. If your truck uses diesel, this is a nonissue for you. Diesel engines don't pre-ignite because they inject fuel at the time of combustion.

What Is Ethanol?

Ethanol fuel is a renewable fuel source made from corn or grain. It can be found at many fuel stations and is prevalent in the Midwest; a notice at the fuel pump will say that the gasoline contains up to 10 percent ethanol. Pure ethanol has an octane rating of 110, so adding this to gasoline is an easy way to increase the octane rating. Some stations even offer an E85 selection; that fuel is 85 percent ethanol.

How Does Ethanol Affect My Engine?

A vehicle needs to be properly equipped to run E85. Flex-fuel vehicles are designed to handle both E85 and regular gasoline. Without getting too complex, E85 has a much lower air-to-fuel ratio than gasoline, meaning that it requires more ethanol than gasoline for proper combustion. It also has roughly 20 percent less energy per gallon than gasoline, which means running ethanol will lower gas mileage noticeably. On the flipside, with E85 more fuel is injected to get the proper air-to-fuel ratio, and it has other properties that allow an engine to make more power. To run E85, the fuel must be injected in different amounts into the engine. In addition, other system changes are needed to protect the fuel system hoses and connectors. On the plus side, ethanol can dissolve deposits in the fuel system, which can clog the tiny ports in a carburetor. When using a carbureted engine, it is best to use ethanol-free gasoline whenever possible.

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What Is Biodiesel Fuel?

Like ethanol, biodiesel is made from renewable energy sources such as cooking oils and fats. Biodiesel has less energy per gallon than standard ultra-low sulfur diesel fuel, but only about 7 percent less. B20 (meaning 20 percent biodiesel and 80 percent standard diesel) is the most common application of biodiesel, and it only loses 1 percent energy compared to standard diesel fuel. Biodiesel is biodegradable and won't contaminate soil or water if spilled.

How Will Biodiesel Affect My Engine?

Biodiesel and B20 have reduced emissions over standard diesel fuel, which is a big plus for the environment. Biodiesel has better lubricating properties and can extend injector and engine life over standard diesel fuel. Like ethanol, biodiesel is a better solvent than the standard fuel. For vehicles with existing deposits in the fuel system, switching to B20 from standard diesel can cause fuel filters to clog as it loosens and dislodges deposits. While this isn't a major problem, it does require the fuel filter be replaced more often. Biodiesel can be used in most modern diesel engines, but always check the owner's manual to be sure. The additional solvent properties of biodiesel can damage some rubber components and seals. If the vehicle isn't listed as being B20 compatible, stick with standard diesel fuel to avoid damage.

What Does Top Tier Mean?

The "top tier" fuel designation was first implemented in 2004 for gasoline and fall of 2017 for diesel. A fuel rated as top tier signifies that the fuel meets requirements for minimum detergent and maximum deposit levels under specific test conditions. For owners, that means the fuel they are purchasing won't cause excessive deposit buildup over time. Top tier is independent of the octane ratings of gasoline. Purchasing top-tier 91-octane gasoline over top-tier 89-octane gasoline won't provide more cleaning power since they both meet the same test requirements. Top-tier diesel fuel has similar inherent properties, but it also improves lubricity, stability and protection against water. Using top-tier fuels keeps an engine significantly cleaner than using non-top-tier fuels. This reduces the need for fuel additives to clean the engine and increases engine life.

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Should I Use Fuel Additives?

There are a variety of fuel additives available for gasoline and diesel engines. Depending on the vehicle make and model, driving habits, environment in which the vehicle is operated, its age, fuel type used and many other factors, a fuel additive may be needed. There are additives that help prevent diesel fuels from gelling at low temperatures and additives that clean carbon deposits in the injectors, increase octane ratings, increase storage life and decrease corrosive properties. Some additives can be mixed together and used at the same time, while others should be used separately. Additives may improve fuel mileage, reduce rough idling, increase power and extend the life of fuel. For vehicles in moderate environments, fuel additives should be needed only occasionally to keep the engine running at its best. Vehicles used in harsh environments or that sit for long periods of time may need additives more often. Fuel additives have been known to damage engines when used improperly, so be sure to follow instructions when using additives for a pickup.

How Long Does Fuel Stay Usable?

For engines that aren't used regularly, or are only used seasonally, it is important to take proper care with fuel storage. Generally, gasoline should be used within one month of purchase, but it can last six months when stored properly. Diesel fuel should also be used within one month if possible but can last up to 12 months with proper storage.

What's the Best Way to Store Fuel?

If you don't drive your truck regularly, keep the fuel tank 95 percent full to allow for expansion and contraction. If you need to store fuel for your pickup, it's imperative to use a proper airtight container that has a little space for expansion but not so much that there will be a lot of water condensation. Fuel containers should be stored in a cool place that's out of the sun. Also, different additives have different recommendations for storage. Be sure to check local safety regulations about fuel storage to make sure you're not storing it improperly or in excessive amounts.

If you have any further questions about fuel, feel free to list them in the comments section below and if our readers don't have the answer, we'll be sure to chime in. Also, let us know about any fuel-related issues you might have had. Have you had any positive or negative issues with additives? Have you experienced your vehicle not starting due to gelled diesel fuel? Do you have fuel solutions we haven't mentioned here? Let us know so we can all gain from each other's experiences.

Cars.com photos by Matthew Barnes; manufacturer images


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It is a little simpler than all that. You want your fuel to be fresh, the recommended octane and clean. Alcohol blends like methanol and ethanol, offer superior octane.

Top tier fuel is an expense but you'll appreciate it later on. If you buy (and hold) your trucks to 80 or 100k miles on the odometer you'll see the benefits in the form of cleaner fuel injectors and less trouble with deposits on the valves. Valve deposits can really hurt your compression; dirty fuel injectors are a hassle to clean.

I love Chevron gasoline. It's a few cents more, but their detergent additive is widely recognized as the best. You can even buy it in a bottle. Techron. Good stuff. The other top tier vendors have their own detergent formulas too.

If you're gonna keep your truck more than 20 or 30k miles, but the good stuff whenever you can.

[edit] BUY the good stuff whenever you can.

Buy the cheapest. All gas is the same.

Put the savings into mutual fund

Buy the cheapest. All gas is the same.

El Cheapo Gasoline. Endorsed by sheep-station loons everywhere

Conspicuous by its absence is a discussion of diesel cetane ratings.

Fuel brands are irrelevant. They often share transportation and fuel infrastructure facilities.

The condition of an individual gas station's tanks is actually far more important and hard to determine. Stations that sell lots of fuel are best so that the fuel doesnt sit in possibly compromised tanks for long if at all.

Brand specific additives from the pump are hard to determine and track.

Use the lowest octane rating your vehicle runs on without knocking or ping.

Save your money.

I've been getting over 200K miles per engine without a single fuel system issue for decades this way.

For me, I didnt know that my trucks premium in the 6.2 in which I get 30mpgs. Now that I use premium, I now get 40 MPGs!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!


Please tell us where you get your facts. I got mine from Consumer Reports---they recommended Top Tier gas.

Top Tier gas works! And if you know where to buy gas you will get Top Tier AND the cheapest price, ie. Costco, etc. Educate yourselves.

papajim is playing on your fears.

Don't listen to the fear mongers.

All gas is the same.

Buy the cheapest stuff.

One gas being better than another gas is all in your head.

This is my 20 years experience in the industry talking.

I agree with Big Al.

Consumer Reports was a thing 30 years ago.

What's going on here?

Buy what the manufactures suggest you buy. Plain and simple. The $4 difference in gas each time you fill up isn't much, yes over a year it can add up, but if you can a afford a $50K, $60K truck that recommends premium, then its not a big deal! If you can't then, I suggest getting a different vehicle

Consumer reports are not facts PJ. Its a series of subjective surveys often taken and submitted by idiots.

Samples and random testing usually by local media have proven over and over that the station matters far more than brand. "Bad gas" comes from contamination and age which are most likely at the point of sale. Ask anyone whos ever had an issue its almost always the point of sale.

You can get far more and concentrated doses of techron and other cleaners off the shelf.

What brand of fuel does 7-11, sheetz, wa wa, royal farms, Costco, Sam's, or any grocery store sell?

You think companies don't share/lease pipelines, tankers, refining facilities, trucks? You think they scrub them down every time after a load of exon/bp/shell/chevron go through before the next?

Following CR... talk about sheeping it papadiamondjack when it comes to buying gas.

I'm fine with never having a single fuel issue by buying cheap gas a busy places and throwing some treatment in once or twice a year and the miles have proven to me its fine too.

My truck simply states, "Minimum Octane Rating: 87"

I have an 2011 ecoboost F150 and the difference in using 93 octane vs 87 is 385 hp 430 tq compared to 365 hp and 420 tq. on 87. Of course 2018 ford turns out an amazing 450 hp and 500 tq out of a little 3.5 v6. That is amazing. Have you driven a Ford lately?

Don't listen to Clint. Listen to the papa.


Your ignorance is standing tall before the man!

87 octane for the most part is the same, but anything higher especially 91 octane has additives that add the octane level and make the difference. For the most part gasoline is the same when it comes out of the refinery it is when it is put in the tanker trucks that they add the additives which mix with the gas when the tanker is driven (they call this the splash method). Each brand puts their own additives into the higher octane gasoline at the terminal where the gas is dispensed into the tanker. Gasoline is referred to as LSR meaning Low Sulfur Reformate. Worked for years in the oil business.

The The most important thing to remember about gasoline is not to let it sit for too long. Also you do not want to fill your vehicle up when a tanker is unloading because it stirs up the sediment in the underground tanks. You also want to go to a place that pumps a lot of gas to ensure you are not getting gas that has been around for a while. I usually add Chevron Techron every couple of months when I am filling up my tanks.

@Clint--Having worked for years in the oil business all your gasoline retailers have an agreement to use the nearest gasoline terminal to where they are delivering regardless of brand. Each brand can add their own additives but for the most part except for ethanol they only add additives to the gas blends above 87 octane. Costco claims that they add additives to all their blends and maybe they are right but most brands for 87 octane only add additives like ethanol or any additives that would comply with any local regulations related to clean air mandates. Above 87 octane then each brand adds their own additive to boost the octane level. Gasoline or LSR is usually the first to come out of the refining process because it is lighter then diesel, motor oil, lubricants and then everything else is considered CAT feed meaning it is put into a catalyst and broken down further into polymers and other like products. Refining process is much like a chemistry process. I found the business very interesting

In my area Chevron advertises that it has Techron in all 3 grades including 87

It probably does, it just depends on the brand and what they add at the terminal when the tanker is being loaded. Costco claims they have additive in all their blends and I would tend to believe them. I still put the Techron in every couple of months--ounce of prevention. If I put more miles on I would probably put it in once a month. Costco carries the Techron additive as well and has a very good price on it. I usually fill up at Costco or Kroger (Kroger has the fuel points that add up to a significant savings). There use to be a number of Chevron stations around me but in the last 10 years they have disappeared.

There was some talk that the automakers want the octane level in gasoline raised.


There use to be a number of Chevron stations around me but in the last 10 years they have disappeared....Posted by: Jeff s
Oct 24, 2018 7:16:01 PM

Do you have Texaco stations?

Same gas. You're probably aware that Texaco has been a subsidiary of Chevron for about 15-20 years now.

@papajim--We us to have Texaco stations but that was before Chevron. Remember when Texaco was in all 50 states? My maternal grandfather would buy nothing but Texaco, Even the gasoline he had delivered for his tractors and farm trucks was Texaco and that was dyed fuel for farm use. That was over 40 years ago and now most if not all the farm tractors are diesel and only the diesel is dyed for farm use. I use to have my grandfather metal Texaco gas can for my lawn equipment until it rusted out. Probably should have saved it.

We for the most part have Shell, BP, Super America, and a few independents. There use to be more brands. A lot of people fill up at Kroger with the fuel points. We have several Kroger Market Place stores with fuel stations, restaurants, clothing, toys, and all kinds of things. Also some of the Sam's Clubs and Costco have gas. I usually buy Costco gas when I can because it has those additives for all grades of gas. That is probably the closest I will get to finding Chevron and Texas and then I add the Techron.

I meant Texaco not Texas. Typing too fast. Oh we also have some Marathon but that is more common in Ohio since Findlay OH is their headquarters. Super American is the dominate brand and it is the first to raise prices with the others following. Costco has some of the cheapest gas and it is one of the few with additives in the 87 octane (that is a plus for me).

To the fools that say "all gas is the same", "buy the cheapest"... tell that to people with higher compression engines (people with vehicles that specify 91 octane at the bare minimum). This site really does let just anybody post here. It is a shame that the moderators are non-existent.

To the fools that say "all gas is the same", "buy the cheapest"... tell that to people with higher compression engines (people with vehicles that specify 91 octane at the bare minimum). This site really does let just anybody post here. It is a shame that the moderators are non-existent.

Great article guys: I agree with everything you included about gasoline.

As a former auto tech I can state the following from my experience. Much of it was covered above .

- use the fuel octane recommended for your vehicle and no higher. However, if you live in an area that adjusts gasoline fuel from summer to winter blends, say most northern states and Canada, you may experience pinging in the spring or early summer. If this occurs, and you are concerned, simply move up an octane level for a couple of tanks until the winter blends are used up.( See article above about octane and towing.)

- misconception: using higher octane fuel in an engine designed for 87 octane, will increase fuel economy. Answer is no. Premium fuel is generally used in higher compression, higher reving and boosted engines.
Premium fuels are slower burning and may actually rob you of performance and economy if used in engine requiring 87 octane.

- unless otherwise stated in the owners manual, don't use premium gasoline in your small engine tools (trimmers, mowers blower etc. ) Premium will rob performance from these engines.

No ignorance at all PJ. Since everything I ever own has always run fine on 87 (even 1 car that's manual "demanded" higher) and ALL the non fuel branded stations (the majority) are getting whatever is coming out of the closest terminal I stand justified. You can obsess over tiny amounts of additives that may or may not be added in the right quantity or at all to each and every load that you can get in more variety more reliably and controllable doses at most stores. I will also let you know that first full tank of fuel in your brand new car courtesy of the car dealership will be of the lowest grade of fuel at the nearest pump regardless of what the manufacturer calls for. While when choosing the grade of fuel (octane)manufacturer's recommendations can matter (especially with some specific models) and influence performance (mostly MPG) if the vehicle will operation without ping or knock higher grades are unnecessary. As stated before what really matters is the condition of the fuel (age/contamination) which is often mostly influenced by the amount of time it has sat and the manner in which it has been stored again mostly influenced by the station, turnover and the condition of its equipment. One tank of bad/contaminated fuel will undo a lifetime of loyal brand chasing / humping additive obsessing overpaying.

I buy corn free gas whenever it's available. All subsidies for ethanol should be removed and allow ethanol fuel to stand or fall on it's own.

Gms happens to be correct on this subject.
Wrong on most other, but correct in this post.

@Clint--I worked at a Shell station during the Summers when I went to college and talked to many of the tanker truck drivers. They told me that they load their trucks at the closest terminal to where they deliver and that all the major brands and independents had an agreement to do so. It does take slightly more to refine a higher grade but not a lot otherwise it is the additives to gas which each brand adds to the gasoline when they are loading at the terminal. I do add fuel injection cleaner like Techron every couple of month because it does keep the injectors clean and because I do not do a lot of driving. Most important thing about gasoline is how fresh it is and if the underground storage tanks are not leaking. Do not fill up when a tanker is unloading at a station because it stirs up and sediment in the tanks. There is a certain amount of moisture tanks get from condensation and there is no way to prevent all sediment. The reason I brought up Costco gas is become it is usually less expensive and they add the additives anyway. Also avoid running you tank too low because there is a certain amount of condensation just in your tank from the heat and cold and you get a certain amount of sediment when you pump your gas which you cannot see.

Also if you drive an older vehicle you have to be aware of the ethanol content in gas especially anything older than 2001. Ethanol will eat the seals and hoses on older vehicles. Most newer vehicles are designed to run on E-15 and many are designed to run on E-85. I avoid anything above E-10 on my 99 S-10 unless I cannot find anything else but I make it a point to go to higher volume stations because the gas is fresh.

Additionally you should stick to the recommended Octane level--it is a waste of money to go to a higher Octane. Your owners manual will give you that along with the recommended weight and type of motor oil. I would take the advice of the owner's manual because the engineers that know the vehicle write the specs.

@Jeff S

I'm not the real papajim, but basically you agree with EVERYTHING he said in the very first comment (page UP). He nailed it.

It's too bad the REAL papajim won't be posting here anymore.

Gms happens to be correct on this subject.

Posted by: GM Blows Chunks | Oct 25, 2018 6:24:21 AM

I agree with you for once. Keep posting truths and facts like you did above.

The real papajim will be back on Friday for a chat session.

So it's a known fact that ethanol blended fuel reduces fuel mileage and damages fuel systems. So where is the savings in reducing the amount of oil to make gasoline? Your using more fuel cause it gets less mileage than pure gas. I only see the farmers getting richer.

I always do.

@papajim--I got trolled. I don't disagree but I also stated that it is important to get fresh gas and to use the octane recommended in the owner's manual. I don't see any harm in gas additives and as I said I use the Techron additive every few months. Maybe it makes a difference and maybe not but I keep my vehicles a long time and I would rather take an ounce of prevention.

@ sivicman--I don't disagree but if you choose to run ethanol then you need to make sure that it is safe to use on your particular vehicle. If the vehicle is designed to run on ethanol then I see no problem but I just as soon get the real thing.

"To the fools that say "all gas is the same", "buy the cheapest"... tell that to people with higher compression engines (people with vehicles that specify 91 octane at the bare minimum). This site really does let just anybody post here. It is a shame that the moderators are non-existent." ---- Posted by: Kemo

We've all read articles that try to claim there is no difference between the different grades of gasoline outside of their supposed Octane rating. Supposedly, they say, for a engine built to run on 87 Octane, it will realize no change in performance between that, 89, 91 or higher. I'm forced to strongly disagree due to the fact that in driving many different cars over my years behind the wheel, I've experienced the differences first hand. This started long, long ago when I started putting 100LL AvGas in the tank of one of my 'beater' cars that ran ok on 87 unleaded but burned cleaner and with notably more power on the 100LL.

More recently, however, I used 89 as the standard fill-up on my '08 Jeep JKU Wrangler and 91 in my Fiat 500. Believe me, in that tiny engine the added Octane made for a surprisingly lively little car... maybe not as strong as the turbo version but it sure fell like more than a mere 101 horses from that base engine. In fact, 90 Octane was the recommended fuel, despite its rated ability to use 87 Octane. Once I get past 1000 miles in my Colorado, I'll be putting 89 in the truck, too. At least, I will until the fuel prices rise above $3.50/gallon again.

"Additionally you should stick to the recommended Octane level--it is a waste of money to go to a higher Octane. Your owners manual will give you that along with the recommended weight and type of motor oil. I would take the advice of the owner's manual because the engineers that know the vehicle write the specs." ---- Posted by: Jeff S

--- I disagree and my truck agrees with me. The Owners Manual clearly states to use a MINIMUM of 87 octane and to avoid any Ethanol beyond 15% and to specifically avoid ANY other alcohol-based fuels. It puts no limit on the octane rating I can use beyond that minimum.

- use the fuel octane recommended for your vehicle and no higher.
• And what if your vehicle recommends a minimum, NOT an exact octane rating?

- misconception: using higher octane fuel in an engine designed for 87 octane, will increase fuel economy.
• You will call it a misconception; I'm forced to disagree from real-world experience in several different cars.

-Premium fuels are slower burning and may actually rob you of performance and economy if used in engine requiring 87 octane.
• My personal experience is the exact opposite.

-unless otherwise stated in the owners manual, don't use premium gasoline in your small engine tools (trimmers, mowers blower etc. ) Premium will rob performance from these engines.
• I will agree with the first part, but not the latter. What robs performance is the alcohol in most gasoline that's used to boost the octane rating to that 87; they perform much, much better on non-alcohol 87.

Papajim is traveling this week but i'm his assistant manager's deputy assistant and I know that 87 octane should work great in the The LGZ GM V6, but if you're towing or if 87 octane is making the motor ping for some other reason, you'll be miles ahead if you feed that little motor the gas that it likes.

Ping is so destructive.

GM dealers will not show you ANY love if the black box in that truck reveals a lot of detonation being the cause of ANY engine problem you want to have addressed by the vehicle warranty.

lOOK AT ME- i'M AN IDIOT YAY!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!! i AVE NO CLUE WHAT PREMIUM MEANS, OR MPGS, i SLEEP WITH gmsrgreat AND PAPJIM!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!

My comments above are based on extensive training and experience as and auto technician. I'm sharing that info and experience to help others understand this age old question of which octane fuel to choose.
The fact still remains that higher octane fuels are slower burning. Think about that and how 93 octane fuel would affect the performance of an engine designed to operate on regular 87. Remember, slower burning.

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