Keeping Injectors Clean

I recently had the injectors on my car (23 years old) cleaned, which really helped ? no more ?stumbling? off the line, better MPG, etc. BUT, what?s the best way to keep them clean? Should I use a fuel additive (eg, Techron or STP)? If so, how often? And what about gas? The mechanic who cleaned the injectors said to only use the top octane rated gas from Shell, which seems like overkill. He also said that gas with ethanol should never be used because it burns hotter and can warp the valves.

So, several questions:

? Fuel additives to keep injectors clean? How often?

? Only use super premium gas? Only from Shell?

? Avoid gas with ethanol?

Unless your car was designed to run exclusively on premium gas or unless it has a mechanical problem that ups its octane requirement, you will not get any advantage from using premium gas. In the case of Shell, they have the same additive package in their premium gas that they put in their regular grade gas. And, Shell gas is one of the best, since it is one of the few brands (at least in my part of the country) that meets the standards of “Top Tier” gasoline.

What is Top Tier Gasoline? Several auto manufacturers (GM, BMW, Toyota, and Honda) have collectively established standards for gasoline detergent additives that go beyond the government standards, and the gas brands that meet those higher standards are called Top Tier Gasolines.

Yes, people will tell you that the Federal Government requires a certain level of detergent additives in gasolines sold in the US. However, what they frequently fail to mention is that, during the past 7 1/2 years, the current administration has allowed oil companies to reduce the level of detergent additives in gasoline, and the required additive standard is now significantly lower than it was about 8 years ago. As you may recall, its Energy Policy was written by the major oil companies, during closed door sessions in the VP’s office, very early in the current administration’s first year in office. This just may have had something to do with allowing the oil companies to reduce these detergent levels (he said sarcastically).

So, you may want to take a look at in order to see the specifications for the tests that gasolines must pass in order to meet the Top Tier standards. It is a fairly long list, and it details these standards very extensively in technical terms. The site also lists all of the gasoline brands that meet the standard.

Suffice it to say that most brands of gas do not meet these standards that were cooperatively established by GM, BMW, Toyota, and Honda. Chevron gas meets that standard, but it is not sold in my part of the country, nor are any of the other Top Tier brands, with the exception of Shell. So, I patronize Shell stations whenever I can, and I am lucky to have one near me that charges less than any other station in my area. If I can get gas with a higher level of detergent additives for a lower price, I think that this is an obvious choice.

If none of the Top Tier brands are available in your area, then I can recommend Techron, as it is a very good additive.

I put a bottle of Techron in my '88 fuel injected Accord twice a year. At 217k miles it purrs like a kitten at idle with the original injectors.

Your mechanic was trying to validate himself by giving you professional advice. It all sounds like overkill to me.

  • Fuel additives are totally unnecessary. Use only if you suspect a fuel-related problem.

  • Use only the grade of gas specified for your car, probably regular. All major brands and grades contain the necessary detergents to keep your fuel injectors clean for the nrxt 23 years.

  • Everyone uses gas with ethanol and nobody gets warped valves. 100 million drivers can’t all be wrong.

In short, do nothing special. Just fill up and go.

Best way to keep injectors is to change the Fuel Filter (if the car is equipped with one). I’d start changing the filter more often. On my 98 Pathfinder the change interval is 60k miles. I use change it once a year and it was FILTHY. Now I change it twice a year.

Worked at a GM dealer in Wi. service manager was big on fuel filter replacement I had no problem with the reasoning to change the filter but the threaded fittings on these filters were so often frozen and even with a line wrench you could damage the fittings and now you have a car that you cant change the fuel filter on. (as I remember on side of the filter was threaded the other had a push in line with a plastic retainer and a O ring. What do you tell the customer now?thet he needs the whole fule line replaced? The shop rule was if the fitting was frozen the Service Advisor would contact the customer before any damage done, most declined the line replacement and just drove with a filter that needed changing due to exceeding mileage specs. Would you think a little silver anti_sieze on the threads would keep those that you were able to get of from siezing for the next change.

VDC is one of the most knowledgable posters here, however on this issue I have to respectfully disagree. If the vehicle is run regularly there are sufficient detergent additives in all major brands of gasoline. And they’re all basically the same. Nova had a special on the entire distribution system recently including the formulation and addition of teh additives. The individual research labs within the industry have pretty much all arrived at the same addditive package.

And…back to my point. How many miles does this engine have on it, and what type of driving is it? Any engine not run regularly will develop deposits, and it sounds like that may be the real problem. Perhaps in your case additives are a good idea simply to compensate for the low usage. If that’s true, I’d also suggest gas stabilizer.

Mountainbike–I appreciate the compliment, and I want you to know that I also consider you to be one of the most consistently valuable contributors to this site, but I have to ask, respectfully:

Do you think that GM, BMW, Toyota, and Honda are running a scam in conjunction with a few oil companies?

All I can tell you is that a friend of mine had some fairly serious driveability problems (severe hesitation, as well as rough idling)–for a period of several months–with his '01 Accord, and the dealership that serviced his car was of no help in improving the car’s performance, despite changing spark plugs and filters and allegedly addressing the problem.

I suggested that he switch to Shell regular gas. After about 3 weeks, he reported that the driveability problems had disappeared. After driving his car, I had to agree with him that the car was performing better than it had for several months. Coincidence? Possibly. A result of using gas with a better additive package? Possibly.

While this theoretical improvement in performance as a result of using Top Tier gasoline is not really proveable, since he patronizes the Shell station that I use (the lowest prices in the area), and has had very good results, I think that it is safe to say that he has not done anything to harm his engine, and he has very possibly done something that helped. In the meantime, he plans to continue using Shell (particularly from that low-priced station), and so do I.

No, it is not proveable, but…

The mechanic who cleaned the injectors said to only use the top octane rated gas from Shell, which seems like overkill. He also said that gas with ethanol should never be used because it burns hotter and can warp the valves.

Time for a new mechanic.

  • Repeat after me: “High Octane gas does not help an engine that does not need it. Octane is not a measure of quality or power or cleaning ability.”

  • No one oil company makes “better” fuel than the others. With few exceptions they are the same no matter what the name on the pump says.

  • Ethanol is required in many areas during some parts of the year and it does not harm engines.

[list] Based on your experience with that car I suggest using a good injector cleaner every 10 -20 years. Most people never need it.

Use the fuel recommended by the manufacturer of the car. If it says USE Only High Octane, then only use High Octane as using something else could damage your engine. If it recommends high octane, the choice is yours, but using regular means you will get less mileage, and less power. Likely you will not save any money. It will not damage your engine.

Avoiding ethanol will be difficult to impossible in many areas, especially during the winter. Ethanol will give you a little less mileage and power, but most of the time it is only 5-10% and that is not likely to be noticed. [/list]

Thank you sincerely.

The reality is that all of us have access to only our own experiences, the experiences of those we know, our science courses (I took mine back when the atom was thought to be the smallest particle) and PBS shows on this question. We have no insiders on the forum. And, no insider information on regional variations.

Naw, I’d have to be even more paranoid than I already am to suspect a scam. Shell is certainly good gas, and they may even have entered into an agreement with the manufacturers such as providing gas for company racing programs, prototype testing and fleet vehicles, and such in exchange for their being recommended. That would not be a conspiracy or a scam, just an intelligent business arrangement.

However, in the OP’s case I still suspect that the injectors are gummed up due to lack of use. A 23 year old car should have a ton of mileage, and the OP doesn;t even mention mileage.

I agree, shell is among the top companies and should be patronized.

I agree, shell is among the top companies and should be patronized.

Unless you live in a area that doesn’t have Shell gas. I know of 2 shell stations in NH…and 1 on MA.