95 RON or 99 RON?

fnc

Guest
hey im currently running a 1.4 ibiza dab, and im justing looking at little ways to make it slightly faster and was wondering if someone could explain the differences between, unleaded and super unleaded, advantages and disadvantages if it would make my car faster

thanks
 
Mar 16, 2008
692
0
Wiltshire / Bristol
The RON rating is how stable the fuel is. The higher the octaine rating is, the LESS reactive the fuel is. This means that the ignition timing can be advanced, with less change of pre-ignition causing damage to the engine and loss of power.

The higher octaine fuel will only be effective on a higher performance engine, and will make no difference to a standard 1.4 except perhaps having a few morw cleaning chemicals in it. In summary, it will make no difference to your engine, just your wallet!
 
Apr 27, 2008
900
0
he speaks the truth unfortunately :cry: i have the same car as you mate and iv tried the it. There isn't alot you can do to improve the power, i have a bmc cda induction kit and a cat-back exhaust which seems too add a little more kick but tbh 100bhp from a 1.4 isn't to bad in the first place :)
 

kriso

_______ C U P R A _______
Jan 29, 2007
2,325
4
Brighton
All the mk4 Ibiza petrol engines are designed to run on 95 RON. 99 RON can increase performance if your ECU is mapped for it but otherwise it won't make any difference unless it also happens to have better detergenats or additives in it.
 
Mar 16, 2008
692
0
Wiltshire / Bristol
well i run vpower in my 1.8t and i feel it run alot better and who else run vpower in there 1.8t

I think the 1.8T will benifit from 99 fuel.

From what I understand, the 1.2 / 1.4 petrol is designed to run on 93 - 95 RON fuel, so you would get a benifit from running 95 over 93 (dont think 93 is available in UK, but is in europe as their fuel quality is less than ours). The 1.8T is designed to run on 95 - 99 RON, so will run fine on 95, but will benifit from 99.

Hope that makes sense?
 

kriso

_______ C U P R A _______
Jan 29, 2007
2,325
4
Brighton
well i run vpower in my 1.8t and i feel it run alot better and who else run vpower in there 1.8t

Yea that's because of the detergants/additives. As said, all the engines are designed to run on 95 RON. 99 shouldn't make any difference according to the engine specs :shrug:
 
Mar 16, 2008
692
0
Wiltshire / Bristol
Yea that's because of the detergants/additives. As said, all the engines are designed to run on 95 RON. 99 shouldn't make any difference according to the engine specs

Just checked my owners manual, and it doesnt have any petrol engine bigger than the 1.4:rolleyes: so cant check - But ill beleive you. Im still sure that I read somewhere the 1/8T would benifit from 99RON though, but as I cant find it, ill accept your correct:)

I did check my old manual for the mk3 (forgot to give it when I PXd it) and it said the 1.8 was fine on 91 - 95 RON - so your theory does indeed sound correct:think:

I bow to you superior knowledge:p
 

Nath.

The Gentlemans Express
Jan 1, 2006
8,620
16
EASTLEIGH, HAMPSHIRE
Had a few tank fulls of VPower and it did nothing.

If it was to do anything it would only be 2-3ps so nothing that the average human could detect.

If you are super human and you have a calibrated rolling road built into your arse maybe you could tell 100ps from 103ps but I can't.

IMO if your car runs smoother or better on 99ron then you have a fault (or a map setup for it) ,my poxy 1.8t 150 runs silky smooth on 95ron
 
Last edited:

stezo2k

Anjuna Monkey
Mar 15, 2008
2,804
1
Dudley
i'm running a 1.2 myself though many will say 99 oct shouldnt make a difference i can personally tell

accellerating seems smoother with the 95 stuff whereas with the 99 the ride isnt as smooth but ever so slightly more responsive

maybe its a placebo but i think it does make a slight difference. plus 99s better for your engine
________
The cigar boss
 
Last edited:

kriso

_______ C U P R A _______
Jan 29, 2007
2,325
4
Brighton
plus 99s better for your engine

That's what the petrol companies want you to believe ;) It even says in the manual higher octane can be used but will make no difference. The engines just don't run the kind of power or compression ratios where it would make a difference. All that really matters is the additives.

Civic Type-R engines are meant to be fed higher octane or it will affect the warranty. But these european engines are designed to work with the types of fuel available over here.
 

TiGeR89

Guest
my 1.2 seems to be more responsive with 99octane, certainly on accel... mind u the engines only dne 12000 so its still quite new.
 

225

Full Member
Feb 8, 2004
1,836
0
uk
Visit site
Turbo'd and big engines benefit more from using 99 ron fuel and their ECUs can adapt to them. However certain engines like certain fuel. I found the LCR and tvr really didnt like BP ultimate but loved Optimax and the tvr really liked Tescos 99 ron, popping and banging on lift and had a little extra go.

Do a few garages in teh UK still sell that 102 ron or what ever it was?
 

bertrum

Guest
According to AutoData, the 1.4 16v 100hp engine (as in the OP's DAB) should be run on a minimum of 97ron. Mine drives much smoother and power is more consistent with Tesco 99 than any other fuel.
 
Oct 17, 2006
2,141
0
Mid Wales
According to AutoData, the 1.4 16v 100hp engine (as in the OP's DAB) should be run on a minimum of 97ron. Mine drives much smoother and power is more consistent with Tesco 99 than any other fuel.

Given the choice between autodata and the manufacturer, I'd take the manufacturer's opinion!
 
SEATCUPRA.NET Forum merchandise