STP GST60300EN12 Oil Treatment for Petrol Engines 300 ml

I use this in a Ford Capri 2.0 to add a bit of extra zddp to the oil to protect the camshaft. Plus the engine has done 100k miles, so the extra viscosity keeps the oil pressure healthy. It may just be my imagination, but I'm sure the car runs quieter and cooler with this in. I add it to the 10w/40 semi-synthetic oil Ford originally recommended for Pinto engines, and it seems to alter the viscosity to approximately that of a 15w/50 or 20w/50, judging by the oil pressure gauge (and how it flows when I drain it). All in all brilliant for a classic engine, but probably not a good idea to put it in a post-millennial vehicle.

As servicing mileage is increasing anywhere between 10,000m ~ 20,000m to support your synthetic or mineral oil--I would recommend using STP after every service to improve it's viscosity !! The best way of using it is to boil a saucepan open the STP bottle & let it simmer for about 10 minutes so that the STP is liquid & easier to pour into the engine without wasting any STP is also excellent for older engines where parts are beginning to wear & need better lubrication particularly valve guides & big-end assembly

Rather smaller than what I expected

Having bought my granddaughter a 10yo jalopy for her 18th birthday, I decided a tad of engine care wouldn't go amiss! I have used STP additives since I was a poor student myself (many moons ago) and have never regretted it. Prevention is always better than cure! This time the car seems to be happier and running smoothly. Let's hope it stays that way! Remember to closely follow the instructions on the container.

I never really know how well all these car products such as oil addictives or fuel additives actually work or benefit my car, but at such a cheap price they're worth ago. Personally half an hour after adding this oil additive to my engine, I felt that the car drove more quietly and possibly a little more smoothly. I'll definitely be using it again in a few months.

I like to use this on diesel engines, as I believe it cleans the engine better than on petrol.

Didn't really help

Added to 10-40 oil + renewed oil filter haven't been out on bike since I done oil change so can't comment. My friend is a mechanic and he highly recommends all stp products.