high octane fuels/fuel addatives

1. wicked-vtr Saxperience Forum Bum Joined: Jan 2009 Surrey Posts: 2608 200sx s14a mark 1 vts

   #1 14th February 2009, 13:36

   i usually fill up 95 octane fuel, yesterday at the pumps i found myself wondering is it worth paying the extra for the "super" unleaded or 98 octane or whatever it is? any gains MPG/power wise?
   also, my mate gave me a bottle of NOS fuel addative stuff from halfords, will it make any odds? and is there any adverse effects to using additives like increased engine wear due to the bigger explosion?
   just thought it would be interesting to see if this stuff actually works
   
   cheers
2. user_26566 Established Member Joined: Aug 2008 harlow/ essex Posts: 1414 stealth Vtr/S

   #2 14th February 2009, 13:38

   nos fuel wont do anything lool but for super some time i use it and it fell abit smoother when accelerating btu other than that i dont think there is much difference !
3. dan-dan Regular Poster Joined: Oct 2008 Nottinghamshire Posts: 334 Saxo VTR W-reg Escort RS turbo with about 160bhp

   #3 14th February 2009, 15:42

   its more of a cleaner burn mate than anything else, no more power for a N/A car well not to noticable power but a turbo'd car would notice the difference. as the fuel is less prone to pre-ignitioning in the chamber. with the obvious positive pressure in the cylinder and extra heat generated.
4. JamesRm Forum Section Moderator Joined: Aug 2008 Liverpool Posts: 15517 Saxo VTR

   #4 14th February 2009, 15:45

   i used to use high octane fuel with addatives and my fuel filter went and the car want running right for ages, i dont advise you use it often.
5. user_21524 Established Member Joined: Feb 2008 wirral Posts: 2087 saxo vtr mk2

   #5 14th February 2009, 15:53

   unless your car is mapped for it will make no differance tbh
6. Toad Saxperience Post Whore Joined: Mar 2007 Reading Posts: 8980 French tin can

   #6 14th February 2009, 20:39

   Run fuel with the octane level your car is mean't to use. Too low, or even too high a rating, can be bad in different ways.
   
   I have to reply to a few of these comments...
   
   - Octane booster will not give you smoother acceleration.
   - There isn't a bigger explosion in the cylinder.
   - Premeium fuel tends to be better quality, and can potentially give a greater energy release, however, if the RON value is not fit for you car, don't use it.
   - A cleaner burn? Using a fuel with a RON rating which is too low for your engine will typically cause detonation. End gasses in the cylinder will combust on their own accord AFTER the ignition stroke. Pre-ignition is completely different, and refers to the air / fuel mixture igniting far before TDC. It's also very dangerous.
   - N/A engines, and especially N/A racing engines, tend to run high compression ratios and when matched with ignition timing, higher RON rating fuel is required to avoid detonation. Remember, higher RON rated fuel is actually less combustable than lower RON.