Just out of curiosity, what do you guys think about those Oil additives that STP and others make ? I was wondering if it would benefit my Elderly Honda engine or if it would do more harm than good. Thoughts and ideas? How about the “complete” fuel system cleaner ?

STP is a “Viscosity Index Improver”. Translation: It will make your oil thicker. How thick? Nobody can predict this, as we don’t know the current viscosity of your oil. All I can say is that I would personally avoid this stuff, as you could wind up with oil that is too thick to flow properly, p…

I always recommend against STP, unless you have a wornout engine and you want to get one more summer out of it. I’ve never used STP since my student days car (57 Plymouth, well worn) and have not overhauled an engine since the summer of 1964. Modern oils have all the aditives you need. Fuel system c…

I have a slightly different take on STP. Many ago I was responsible for all operational decisions and work in a very large high speed production plant. I had my guys just finish a major “to the floor” overhaul of a production line. We had just started it up and were running it without making product…

A production floor INSIDE is far from real world experience. Tell me how well STP works when you try to start you car at 5am after it’s been sitting all night at -15. IF it even turns over there’s a very good chance it’ll be toast long before the engine reaches operating temps.

You don’t need this additive unless you have a near worn out engine. Mike is exactly right about STP and cold winter days. It’s going to work the battery and the starter motor much harder; if it starts at all. Many years ago I worked for a small town Subaru dealer. Subaru at one time required, and…

For the oil thickening, you don’t have to mix anything, pour anything into a running engine or jump through any hoops. A can of straight 30W motor oil is the same price as any other quart of oil. Two quarts will thicken the mix even more. Don’t work harder or expensiver; work smarter. If you have th…

Two facts. A friend of mine had a '78 Chevy van with a 350. He changed the oil twice a year and always used STP. last time I saw that van it had 380,000 miles and was still going. It was on it’s third transmission… The heads and oil pan have NOT been off this engine. When resizing cartridge cases i…

What about your elderly Honda engine do you believe needs help? If it is not broke, don’t fix it.

What year honda? What size? How many miles?

STPs label once read THE RACER’S EDGE. Well, racing engines are LOOSE engines. The clearences for pistons and bearings are very loose and require a great volume of oil and a thicker oil. Late model engines are built to very close tolerance with very tight clearences which call for thinner oils. I ha…

STP Oil Additive good or bad?

Maintenance/Repairs

vipergg December 8, 2019, 12:47am 19

The only additive I have ever found that works is something called Tufoil though its been many years now since I used it though they still make it . When you used that it would start easier and noticeably ran and idled better . It wasnt cheap though at about $12 a bottle per oil change. If you have a sludged up engine something called Auto-RX is a good cleaner that gently cleans the internals .

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STP Oil Additive good or bad?

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