Good morning Jag Family. Quick question. I added some fuel additive lucas injector cleaner a while back. Well i was reading the manual and i ran accross the part that says .... don't add any type of additives.

So my question is... does oil and gas additives really do significant damage or is that just a warranty deal???

Thank

 

Don, i have been adding additives to all of my vehicles for years, including the Jag. Really, I will put these into 2 different groups and you will see why.

The first group are the gas/fuel injector additives, radiator cleaning, and oil detergent additives. These you can do all day long, no crime no foul (within reason of course). these do nothing more than remove some build up and that is about it and for the most part, are pretty benine. They do help in the big scheme of things. Where you can run into issues is on the older vehicles, a lot of the seals are not designed for the more acidic products made currently. Also, a lot of manufacturers can't garantee what you are going to add. So, they make a blanket statement to cover their butts. Kinda like running E85 in a car not designed for that. It will run for a short period of time, but the seals on say the fuel injectors will fail shortly thereafter if they are not of the correct design.

The other additives (too many to list here, but I will point out a few of the more common ones), these can get you into a world of hurt in a heartbeat. Anything that says "stop leak", stay away from unless you are in a dire emergency and have to get the car out of a hazardous situation. I've heard too many stories of someone using these products and causing significant work for some technician, resulting in numerous hours and high repair bills. Think of it this way, you add a think of radiator stop leak, it will more than likely stop the leak in the radiator, but how, by coating everything with a layer of goop. Gee, now your radiator has an entire layer of goop in it and now it won't cool the motor as well. Your water pump has this stuff on it too, now that can't pump as well. The coolant channels inside of your block has this stuff in it restricting the flow of coolant there and leading to higher temps. How do you get this stuff out, tear down the motor, boil the block, new water pump, new radiator, you get the idea. Another one that I fear every time seeing it is the "fix a flat" products. yes, they will get your car back on the road. But again, you are sliming the inside of the tire with this goop. If you don't drive the car for the recommended time, the goop will collect at the bottom of the tire. Imagine the imbalancing that can cause (you think tossing a 1/4 ounce weight is hell, imagine up to 12 ounces of imbalance). Also think about when you remove remove this tire now. You will have that stuff all over the rim and tire that will now have to be peeled off and removed so you can remount a good tire.

You also have the oil additives (not detergents). These are really nothing more than thick oils that have better coating properties. Unfortunately, the newer engines rely on a very thin oil layer between parts. So, getting the oil thickness too high can lead to essentially running parts with no oil in there. I'm sure you can see the problem there. You also have the silicon oil additives which help to maintain the thin oil qualities and as for their overall effectiveness, I can't say that I have heard anything that I would consider unbiased on how it made improvements. I see it as adding something to the car that doesn't benefit me. So, why waste the money?

There are also the tranny additives. Again, this is a very dangerous slope to be on. I'm sure there are some that do a good job (none come to mind), but you get the wrong one and now you are gooping up the inside of the tranny and plugging up lines and whatnot. How long do you think your tranny will like that?

If you are in downtown LA/NYC/major town and you are in fear of your life. By all means use these products. Much easier to replace a car than someone. So, do your homework first.

 

Gasoline has all the additives required already blended in- no 'supplements' are needed.

Oil and coolant also.

Save your money.

 

Good write-up Themo.. I've always had my suspicions about additives, but you've shed a whole new light on this. Thanks for the info. i'm sure others will find it insightful. Keep up the good work

 

Note - I am a total sceptic, but I think the occasional injector cleaner is a good thing. My car got a shot in the arm when I ran a bottle of Techron through it. It was probably in the range of 10hp (back to stock performance, not beyond) if I were to guess based on my dyno experience.

 

Thermo......well said. You covered all the bases. Jack