Advanced Driving Hub

Essentially how much can you get away with? How much is good (or bad) for your engine? I only drive petrol engines but the question stands for diesel too.
Any thoughts?

In my 370z, 125ml per tank completely changes the character of the engine (a LOT more free revving, smoother and eager, even from cold), with correspondingly much easier and sharper (manual...not using autoblip) gear changes. However, I have been wondering: what would happen if I put, say, 4 bottles per tank (that's 8 times more) ?

For reference, I only use Shell V-Power Nitro in the 370z, so that is my baseline when I claim that fuel additives subjectively seem to noticeably improve the operation of the engine and transmission. The added fun and increased engine life-expectancy aside, what are the benefits? Someone asked at the local supermarket if it made such a difference for small-capacity petrol engines and I was not sure what to answer.

ChristianAB wrote:Essentially how much can you get away with? How much is good (or bad) for your engine? I only drive petrol engines but the question stands for diesel too.
Any thoughts?

In my 370z, 125ml per tank completely changes the character of the engine (a LOT more free revving, smoother and eager, even from cold), with correspondingly much easier and sharper (manual...not using autoblip) gear changes. However, I have been wondering: what would happen if I put, say, 4 bottles per tank (that's 8 times more) ?

For reference, I only use Shell V-Power Nitro in the 370z, so that is my baseline when I claim that fuel additives subjectively seem to noticeably improve the operation of the engine and transmission. The added fun and increased engine life-expectancy aside, what are the benefits? Someone asked at the local supermarket if it made such a difference for small-capacity petrol engines and I was not sure what to answer.

You're imagining things. They make absolutely no difference apart from making you a bit poorer than you would have been if you'd put real fuel in your tank. The people who make this junk are having a right laugh at your expense.

I will invite you to drive as a passenger in my car. Then you will stop laughing.

In all seriousness, I might have thought like you when I had only driven my Mazda 6, but the effect I describe is real, as attested by my passengers. Also, in my Mazda 6, the ECU also adapts to the new fuel or fuel additives within the first few minutes, but not in my 370z.

Could you please explain how a fuel additive makes your manual gear changes "easier and sharper"?

Strangely Brown wrote:Could you please explain how a fuel additive makes your manual gear changes "easier and sharper"?

In much the same way that a £100 HDMI cable gives more vivid and realistic colours than a cheap one from the pound shop.

Two or three years ago my car spent a few days in a bodyshop for a bit of attention. When I collected the car and drove it the short distance home the exhaust smoke was quite bad. A couple of days later, not having been driven in the meantime, it went for MOT and failed on emissions, so I gave it a dose of Fortes Diesel Fuel Additive/Injector Cleaner, took it for a spirited drive and back for retest, which it passed OK.

My guess is that while the bodyshop had the car they must have started it up and moved it about a few times, causing the injectors to get coked up, or something like that. In this case it seems fairly clear to me that the additive was beneficiial, but I wouldn't use it normally, and certainly not in large quantities. By the way, I stopped using supermarket fuel several years ago, and now only use normal grade diesel from BP, Esso or Shell, which appears to give better fuel economy than the supermarket stuff.

Best wishes all,
Dave.

Dave, the "spirited" drive probably did as much (or more) good than the additive

TripleS wrote:By the way, I stopped using supermarket fuel several years ago, and now only use normal grade diesel from BP, Esso or Shell, which appears to give better fuel economy than the supermarket stuff.

I'm fairly sure Esso is exactly the same stuff as supermarket fuel. BP probably the same. Shell is at least different.

Edit: they may add additives at the station, I have my doubts, but additives shouldn't change your fuel economy.

trashbat wrote:Edit: they may add additives at the station, I have my doubts, but additives shouldn't change your fuel economy.

Those of us old enough, may remember "Formula Shell" (late 80s) - it did improve my economy by about 10%. Unfortuneately, it also buggered small Vauxhall (amongst others) engines. That was an additive, put in at the filling station by the tanker driver when a load was delivered.

ChristianAB wrote:I will invite you to drive as a passenger in my car. Then you will stop laughing.

I'm not laughing. I don't sell the stuff.

It seems to me that, no matter what the hobby, there's no shortage of fools out there who will spend vast amounts of money on things that make no provable difference outside of their own imaginations.