Best fuel additives for petrol engines?

[20VT_AUQ]

Hey all I have a 2003 1.8T AUQ but I guess the same would apply to any petrol engine from those years.

Do you use any additive? My car usually drinks Shell V-Power 98 octane (in my country it is either 95 or 98 octane gasoline). Sometimes I put Repsol Neotech 98 octane which is also good quality, not sure if there is Repsol in UK but it is very popular in Spain. Although I have the impression that Shell or BP are best (we don't have BP in my city unfortunately).

Although I use high quality fuels that contain good stuff in them, I occasionally toss some "injection cleaning" additives, like 3 or 4 times per year. Tried some of them and the car seems happy or it might be the placebo effect, but for the overall small cost it feels like a good idea in my mind. The ones I like the most are Wynns Petrol Gold and Liqui Moly Injection Reiniger whereas with other brands like STP or 3CV felt like nothing happened. But you never know.

What are your experiences with these products? Your Leons like em?

 

[rafletcher]

If you're using the V-Power or equivalent fuels, they already contain the detergents for cleaning the injectors, so I'd say it's placebo

 

[oilman]

If you're using the V-Power or equivalent fuels, they already contain the detergents for cleaning the injectors, so I'd say it's placebo

I agree with this.

 

[andylong]

Shell V power has an octane booster and an agent for promoting cleaner burning.

It has surfectants which clean off deposits, but how much I do not know . All fuels are required to have a detergent action.

I have always viewed the more expensive fuels with suspicion, struggled to find any evidence ( an actual scientific test, not anecdote or marketing information) to support that they are better cleaners of injectors etc, but have used additives myself.

If you are already paying extra for fuel, I doubt that more additives will have any further effect.

Gasoline, low boiling point naphtha 86290-81-5 289-220-8 F+, Xi, T, Xn, N R12; R38; R45; R46; R63; R65; R67; R51/53 80.00 - 100.00 %
Ethanol 64-17-5 200-578-6 F R11 0.00 - 5.00 %
Methyl tertiary butyl ether 1634-04-4 216-653-1 F, Xi R11; R38 0.00 - 15.00 %
Ethyl tertiary butyl ether 637-92-3 211-309-7 F, Xi R11; R38 0.00 - 15.00 %

 

[Alexis27]

I recall a Shell technician in an article about F1 fuel saying it takes about 3000 miles for VPower to do a full cleaning cycle in your road car.

 

[20VT_AUQ]

I recall a Shell technician in an article about F1 fuel saying it takes about 3000 miles for VPower to do a full cleaning cycle in your road car.

Yeah I guess the additives are just more concentrated and "quicker" than regular fuel.

 

[Rich.T]

Ive gone off of additives. I used to use them in my pd 150. Seemed to make the car run smoother and more responsive. But again, could have been placebo. But then soon after id be removing the down pipe and clearing out the turbo.
Weather its the cleaner shifting the crap through the engine or the low mileage i did, i dont know. Could have just been a coincidence. But its sort of put me off.

Now im in a petrol car i just use premium.
That being sead, there have been a few occasions that ive put the cheaper stuff in. Slightly less additives and less aggressive to the fuel system.
What harm can it do?

 

[oilman]

What harm can it do?

In a nutshell... None.