Fuel additives

ALLI

ALLI

ALLI

Associate
Joined
9 Jun 2004
Posts
1,705
Location
Lovely Wolver-ampton!
Seems to be loads of them now at Halfords. Surely fuel has the majority of these already in them?

So, has anyone actually proved the increase BHP, mileage, performance etc? Or are they generally a load of cack?
 
I thought that might be the case. So how are they allowed to sell them with such claims of supposed benefits? Surely trade descriptions act??
 
i once stuck a bottle of wynns injector cleaner/power restorer in my old mondeo, made no difference at all. i might try some better stuff in my new mondeo its upto 130k so additives might help slightly
 
JIM_BOB7813 said:
IIRC Fifth gear did a test and found no improvement, one product actually decreased performance also.
edit:
http://fifthgear.five.tv/jsp/5gmain.jsp?lnk=401&featureid=931&show=s12e5&section=Consumer
Click to expand...

They all reduced peak power by 2% with one managing to reduce it by 6% (based on the fifth gear test).

I just love the second comment on the youtube link though:

youtube poster said:
If the engine they used was turbocharged there would have been a huge power increase!
Click to expand...

:D
 
The problem with the fifth gear test was that it used a 1990 era rover k single point injection engine.

The single point injection engine was a glorified carb car without what we would see as proper engine management, what they should have done was use a modern engine with a proper engine management system to run the test.
 
All a load of rubbish and I found none of them added any more power to mine so I just use the straight lead replacement additive now (it's a vintage engine without hardened valve seats)

Basically I run mega compression on the old engine and get detonation problems if the timing is too far advanced so the added octane should allow me to run the timing less retarded and get extra power. It doesn't. I just keep it backed off and use the straight lead replacement because it's the cheapest.
 
M0T said:
The problem with the fifth gear test was that it used a 1990 era rover k single point injection engine.

The single point injection engine was a glorified carb car without what we would see as proper engine management, what they should have done was use a modern engine with a proper engine management system to run the test.
Click to expand...
Even with a knock sensor and variable spark timing on the ecu I honestly think these products add so little to the fuel that it makes no difference.
 
Jonny69 said:
Even with a knock sensor and variable spark timing on the ecu I honestly think these products add so little to the fuel that it makes no difference.
Click to expand...

I completely agree, but at least if they'd done it on a proper modern engine then I wouldn't get my clueless mates telling me it was done on some old rover lump so the test doesn't count.

Makes more difference to put some decent fuel in instead.

Edit: Cheaper too, costs £4 extra for v-power over standard petrol for a tank for me, and most of those things are £5-£9, so cheaper to use the decent fuel.
 
I tried some octane booster once when I filled my car up with the 97 RON that I usually use. It made a difference for sure! The engine felt smoother and slow acceleration through first and second was a lot smoother, too.

This is probably just down to the fact my car is tuned to be run on 100 RON fuel, though, so with the octane booster its just running how it should be.
 
My Mondeo TD had been a bit sluggish recently and a pig to start (not helped by knackered glowplugs!) I had a chat with one of the DAF mechanics at work & he suggested an additive which he described as "The automotive equivalent of caustic soda" :eek: "It may #@*& your fuel pump, but it should be ok!" :eek: erm, "Ok" I say what the hell..... :p

Suspecting dodgey injectors, he put some of this compound into the tank (about 1/2 litre) and told me to drive it normally through the week, for a day or so, I noticed a lot of soot as I "accelerated" (loose term not generally applicable to a Mondeo TD!:D) but the car was definately picking up noticably better.

A week later and the difference is almost night & day, the cars almost enjoyable to drive - its a tractor spec 1.8TD FFS! - and it feels far happier lugging along @ low rpm where previously it wasn't.

Having previously tried Diesel Redex which the mechanic described as Cat's Urine its clear to me that some additives work and others don't.

I need to find out exactly what he put in it now. :o:D

:)
 
Last edited:
Been using Millers "Diesel Power Sport 4" for a while now when I can't find BP Ulitmate Diesel. I find if I run the car on supermarket diesel is smokes, rattles more and has a noticable performance drop.

According to the bottle, it increases the diesel cetane by up to 4 numbers. Haven't really got a clue what it means but iit does work.
 
Jonny69 said:
Even with a knock sensor and variable spark timing on the ecu I honestly think these products add so little to the fuel that it makes no difference.
Click to expand...

Thats the key I think, when you see these products they say it adds 1 or 2 points of octane which really means 0.1 or 0.2 octane, when you can buy fuel at 95 to 97 octane. There just isnt enough, if you measured out a good 20% + of toluene and xylene to fuel I would expect it to work.
 
Last edited:
I use Millers VSP in my old Guzzi as it was designed to run on leaded fuel, it supposedly increases the octane by 2 octane number. In a 28-year old bike with barely 40hp it's hard to tell any difference in performance, but that's secondary to protecting the valve seats.
 
Pyscho_Si said:
Been using Millers "Diesel Power Sport 4" for a while now when I can't find BP Ulitmate Diesel. I find if I run the car on supermarket diesel is smokes, rattles more and has a noticable performance drop.

According to the bottle, it increases the diesel cetane by up to 4 numbers. Haven't really got a clue what it means but iit does work.
Click to expand...

I also use Millers and I've noticed a small difference. :)
 
they only "up" performance on cars that are strugging in the first place. Ie my 1.25 fiesta had a blockage in 3 and 4 injectors, it ran "ok" but had absolutely no power (relative to what it normally has). the Additives seemed to clear it through. The Tesco's one didnt work though. lol
 
You must log in or register to reply here.
Back
Top Bottom