Redex

[Mav2006]

Hello,

Does anybody have any thoughts on fuel additives? I use Redex a few times is it worth it?

[onzarob]

I used the once only redex treament from halfords and it made a noticable difference. getting 2 to 3 mpg more now. If you use the more regular treatments don't over dose the tank as this may cause it to smoke a little more until you fill up again.

Rob

[RickT]

just noticed you have a Passat 1.8t spt 2003 - i would not bother putting it in that... just use decent fuel, ie Shell Opitmax or BP super Unleaded,

On a older car, yes it helps.. on new.. dont waste your time... also if you put too much in... it runs poor and can knacker the CAT if it does not burn correctly.


RickT

[Mav2006]

Thanks for the reply. In your opinion do you think it's worth paying extra for Optimax or Super unleaded, rather than supermarket fuel. Also I'm never sure if I can use super unleaded in my car? Thought my hand book says 95 RON, thought super was 98??

[onzarob]

Super unleaded petrol ie 98 RON has a higher octane value, making it more combustable. In a high performance engine it will help it run smoother and you'll get more MPG. I used to have an alfa 155 and when i put 98 ron petrol in it used to run quieter and smoother and i'd get more MPG. the only down side is the goverment in there wisdom decided to tax it more, making it slightly more expensive which is crazy as you get more MPG. Green tax they say....not really!!

Rob

[devonutopia]

For diesels I've found Millers diesel power plus gives me good gains on power and economy - and there's a new millers diesel sport 4 out now which is supposed to be even better for diesels. I can't wait to get some.

[RickT]

going back to the fuel thing.... we can go on for hours!! but as said above.. to cut a long story short... i get less miles and a poor performance on 95, yes the handbook says 95 on my also.. but they will all run on 97/98.... the best one for performance is TESCO 99 octance i find! but its 15 miles from my house to the pump!! so only when im passing i fill/top up with that!

try running a tank or 2 97 or Shells Opitmax/Vpower and see what you find.. as i say... i get about 50 miles at least extra per tank... yes it cost more and if i used the other 95 stuff it would work out the same in price in the long run... but its the performance i perfer..

RicKT

[MalcQV]

95 RON vs 97/98 RON, really depends on the car. Most modern engine management systems can differentiate the difference between the two fuels and you can gain the benefits from using higher octane fuels.

Optimax is also supposed to help keep the engine cleaner. You really need to use it regularly though I think.

Top Gear (mag) and I think EVO did some tests using the different octane fuels. In fact I think EVO may of used a Golf GTi in the test.

[onzarob]

My expeinece on getting better performance is baised on leaded petrol being 98 ron (from memory) and when unleaded first came out your car needed to be retarded to run without pinking (well forget about the valveseat issue here). By retarding the engine you've reduce performance. Malqv your right that a modern ECU engine will adapt reducing the difference. My GTI has the CIS injection system which is static/mechanical so the RON of the fuel makes a marked difference as the engine is setup for 98 ron fuel.

Optimax has other properties which can be gained from fuel additives, but its a pain adding stuff when its already added at the pump

I just get annoyed at the tax level, as you get more MPG. Not a very green tax. (that can be said about all fuel tax.)

......rickt your right we could go on for hours!!!

[Mav2006]

well just filled up my first tank full of super unleaded from Tesco, will see what happens to MPG and performance