Using engine treatments--yes/no?

I have a 2002 Elantra with 143,000 miles on it, and I’ve been wondering if engine treatments are worth the money in general. I also notice that many of them say you only need to use them every 25,000 miles, and I wonder if the level of protection drops off as the miles approach 25K. Would it make sense to wait until you’ve gone 12K to 15K miles, then start adding 4 ounces of engine treatment after each oil change? (3000 miles per oil change is about 8 changes in 25,000 miles, and 4 ounces is one-eighth of a quart of engine treatment.)

I think its highly unnecessary and could be harmful depending on what kind of treatment you are talking about. The only thing I’ve ever used in the last 40 years is Seafoam and then after a couple hundred thousand miles. Half directly injected into the intake and the other half in the tank. Call the fire department ahead of time so they don’t think your house is on fire because it’ll smoke like crazy.

Don’t use engine additives/treatments unless there’s condition where using such a product is beneficial to remedy a certain problem.


Agree, change the oil as recommended, with the right grade, and you’ll be fine.

Are you having a problem?

I do treat the gas with seafome every now and then. Most people don’t, but to me it is like giving a dog a treat, can’t hurt and makes me feel benevolent.

On a regular basis…no. There are some good ones out there like Seafoam and Berryman’s Chemtool B-12 for a failing automatic transmission but use only when necessary.

Today’s motor oils have all the additives necessary for your engine. Usually the only benefit is psychological for the owner. If the car is running well, save your money.

+1 to Triedaq’s post.
And gasoline too. Modern gasolines running modern (extremely clean) engines will give you hundreds of thousands of miles of reliable driving, providing you buy a vehicle with a reputation for long-term reliability, follow the manufacturer’s maintenance recommendations and don’t abuse the vehicle. No additional chemicals are needed.

I keep my car clean and waxed, always did, and a few years ago I came out from Lowe’s and there was a very young employee from the hotel next door that had just pulled up and was admiring my newly-waxed car in the sun. Meaning well, he said “nice car. If you use (I’ve forgotten which additive) with every tankful of gas, it’ll run well for over 100,000 miles”. He seemed a nice kid, and he meant well. I didn’t have the heart to tell him it was already over 200,000 miles. I thanked him and went on my way.

By the way, I never use additives.

@“the same mountainbike” – I do use additivss–2 teaspoons of Geritol in the morning to help clear up my Geezeritis. The main symptom of Geezeritis is thinking that cars of the old days were much better than today"s cars.
The only additive I ever used in cars that I owned was Casite Motor Tuneup. I used it in the 1954_Buick I owned and also the 1978 Oldsmobile. These cars had carburetors and the Casite would loosen up the carbon so that a run on the highway would blow it out.

LOL, thanks for the chuckle. It’s a great way to end the day.
Do my seven daily medications count?

Exactly what brand / type of “treatment” are we talking about here?? Auto-Zone must have a hundred different products all trying to gain access to someones crankcase…

Fuel injector cleaners like Techron do no harm and may do some good if used occasionally.

If you are burning oil and you suspect gummed up oil scraper rings, you have nothing to loose trying an “oil saver” additive that is intended to loosen up stuck rings. Seafoam was mentioned here.

Additives that make seals swell to stop leaks are a strictly for shady used car lots, and make the problem worse over time.

Like I said, I don’t use any but I did have a power steering fluid leak that I used a stop leak on. Don’t remember which brand but the car had a couple hundred thousand on it. The stop leak took care of the problem and never had another leak for the next 150K when I got rid of it.