I've read numerous saying reports oil additives are a waste of money at best and damage the engine at worst.

I do use Sea Foam to de-carb the air intake and fuel system once my cars get up a little in miles. I've had great results with that.

 

My view is that oil additives are simply "mechanic in a can". Ask yourself what problem are you trying to solve? If there really is a problem, then all additives are doing is masking it. If there is no problem, then what is there to fix? I typically keep my vehicles until they have 150k or more. Then they get passed on to others in the family. Its not unusual for someone in the family to have one of my cars or trucks that has well over 200k on them.

Cleaning the fuel system is another matter. While I have never used Sea Foam to clean my fuel system, I have taken the throttle bodies off of high mileage vehicles (75k +) and cleaned them with Gum Out. It makes a world of difference.

 

Avoid em like the plague!!!!lube spray,injector cleaner.fuel conditioner??shure..regular maintanance..keep the bats out of the belfry..no sqweeky sqweeky..thats a good thing..ive seen the inside of enough engines to know..I wont use em..

 

I agree if it ain't broke don't fix it.

If you need an additive then you are using the wrong oil.

Keep with the MFG recomendations and change it when needed and you should not need anything.

I don't use it in a new car but in an old car I have used Marvel Mystery Oil with good results. It has unstuck sticky valves and clogged carbs. Linseed Oil works wonders.

Now with todays electronics I am a little reluctant to use it in a OBD II car.

 

I only use additives when/if there's a problem. When I do.. it's Lucas. Oil, Transmission, Fuel... I use them all and they work.

I had a 91' Camry that used a little oil towards the end of a 3000 mile interval so I started using Lucas Oil Stabilizer... no more oil loss. Same story with a 92' G20. I drove both vehicles up and over the 200K range before trading.

Lucas automatic transmission additive is also great. The Camry would hesitate several seconds before going into gear when you first started out... w/the additive no more slipping.

 

I have an '09 HHR 2Lt.
I used Automotive Engine Restore, mainly because I've put a lot of mileage on the car (currently at 339K)- so I thought i was doing good.
After I put the additive in, the engine starting running pretty rough and my fuel mileage jump 5 min. into the drive. Also had trouble starting a couple of times. Had to take it somewhere to get the oil changed and engine flushed. After doing some highway driving to work (approx. 70 KM, with my heart in my mouth), I put it into idle. It still runs rough but it seems to have settled down overall.

I'm quite surprised as to the engine responding like this. I also have an '07 Chev Impala LS, and I've added oil additives before (mainly because it burns/leaks oil), but never encountered an issue like this.
Any feedback as to why this happened to my HHR would be nice. Google search shows either:
1.> Seemingly high but one-sided reviews from the likes of Canadian Tire, Walmat and Amazon. (I've got a gut feeling that any negative reviews we're "filtered" out
2.> Mixed reviews leaning towards good reviews for older cars (i.e. early 2000s and 1990s, 1980s and 1970s era)
3.> Some bad reviews for some Nissan and Lexus cars (I'm wondering if the VVT engine, as my HHR has it as well, is a common denominator here).

 

[QUOTE=Foxtrot Delta;855787]
After I put the additive in, the engine starting running pretty rough and my fuel mileage jump 5 min. into the drive. Also had trouble starting a couple of times.

Please first clear up " my fuel mileage jump 5 min. into the drive." Are you saying your MPG went down?
Are there any codes?
Engine Restorer is (so they say) to restore compression and reduce oil consumption.
Have you ever changed the spark plugs? If not maybe they were affected by the additive getting passed the piston rings.

 

[QUOTE=Cat Man HHR;855790]
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Didn't see any message aside from the quote from my question. Maybe your post got truncated.

 

Please first clear up " my fuel mileage jump 5 min. into the drive." Are you saying your MPG went down?
Are there any codes?
Engine Restorer is (so they say) to restore compression and reduce oil consumption.
Have you ever changed the spark plugs? If not maybe they were affected by the additive getting passed the piston rings

 

The Check Engine light came on.....I'll be passing by my mechanic to get codes- so I will keep you apprised.

As for the spark plugs suggestion, you may be right. Never considered it. Will buy tonite and try have my guy change tomorrow.

Again, thanks for the quick reply....and I've learned my lesson. Stay away from oil additives like the plague.