When you get gas from a Wal-Mart that has a gas station you can pay extra for fuel additives. $14.99 for a "fuel system service", which is supposed to offer "complete fuel system cleaner", $2.99 for "better mileage", etc.

My question is... is it a good idea to purchase these additives? Will it reduce the maintenance my vehicle needs, etc?

2 Answers 2


Fuels with additives that have passed independent testing are listed here www.toptiergas.com/retailers. I do not see WalMart on that list. The most tested and accepted fuel additive among experienced technicians is Chevrons' Techron product. Fuel additives can have an affect fuel mileage and engine life; how much will be the subject of opinion as there are many variables.

Comments on Additech, the additive that Walmarts website lists.

One assumes a company the size of Walmart would have thoroughly tested the product. The claims made are significant but, except for the mileage improvement, would be challenging to prove.

Claims and comment:

1) Cleaning combustion chamber, intake valves and fuel injectors thus reducing engine knock tendencies: This is an excellent goal. It could improve mileage if the engine has enough deposits to cause the engine controller to have to correct for knock. Top Tier approval would ensure this claim.

2) Friction reduction modifier: The claim here is that the product contains an ingredient that reduces piston ring friction and gets into the engine oil and then reduces friction throughout the engine. Proof is required for this. Others have made this claim and been proven wrong over the years. Modern engine oils are excellent stand alone products not in need of additives. Also, most if not all, OEM's do not approve oil additives and friction modifiers as they can damage the catalyst over time.

3) Anti-ice additives: This is usually alcohol.

Should you buy it? No, due to the lack of certification and the unapproved oil additive friction modifiers.

  • Just because a retailer isn't on the Top Tier program does not mean the fuel additive package is in any way inferior to any other. If you look through the Top Tier FAQ page, you'll see there is a yearly fee involved with becoming "Top Tier". Murphy Oil who supplies gas to Walmart may not want to do this so they can pass the savings onto the customer. Also, do you have any information which backs up your Techron claim? Commented Dec 14, 2015 at 12:00
  • Are these fuel additives worth anything at all? From what I've heard they cause more problems than good, especially the cleaning ones. For example, pouring injector cleaner into the tank can loosen the dirt inside the tank and fuel lines and clog the injectors instead of cleaning them. Commented Dec 14, 2015 at 12:03
  • @Paulster2 The big cost of remaining in the Top Tier program is continuously refining fuel to the standards of the program and passing the required independent tests which is what the fees are for. When a TT refiner ends up missing the mark and gets a non conforming batch they usually sell it to a non TT seller, that seller discounts this less than ideal product. A complete discussion of the fuel refining industry; chemistry, regulation and industry intrigue is a big topic. I know some of it, but I am not an expert. Commented Dec 15, 2015 at 7:19

All of you are misinformed regarding Top Tier. Top Tier requires that every single location in a company's retail brand portfolio contains additives in sufficient quantities and of a certain chemical makeup to be considered TOP TIER. This is accomplished usually by an additive injection system at the terminal level that mixes in the requisite amount of additive as the fuel is loaded into the truck. This works fine for branded sites where the fuel must come from a specific seller - usually a refiner. However, unbranded sites purchase from several different sources based on price at the wholesale level and not all of those sources are willing to pay for injection systems to bring the base fuel up to TOP TIER standards. Fuel additives that are used in the Additech system are manufactured by Afton Chemical and can, in the correct dosage, far exceed even TOP TIER standards. There are also other benefits to the product in terms of lubricity and octane boosters that MIGHT be beneficial to your car or truck. The fuel system cleaner additive at the highest dosage rate will clean your injectors if they are dirty. I use it and recommend it at every oil change. Independent studies, which are cited on Afton Chemical's website, show that deposits are reduced, on average, 69% across a multitude of vehicle types and ages. It works. Do you need it? Maybe, Maybe not. It depends on the condition of your vehicle. The real comparison is spending $20 on the fuel injector cleaning or taking it to the garage and spending much more. It might be worth a try first.

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