98 octane rating

[dyasper]

hi there, i have a 1.8 GDI legnum, is it ok to use a mobil 98 octane rating fuel, will it give me more power... am currently using shell 96...


thanks

[Kenneth]

GDI should be running on 100RON. the higher the octane the better it will run. GDI engines tend to run poorly in countries other than japan.

[dyasper]

is it ok to mix shell 96 with mobil 98 octane

[KiwiTT]

Yes. But try to use Mobil 8000 from now on and the 96 will go.

You may want to disconnect the battery for a minute or two to reset the ECU so the engine can re-tune for the higher octane.

[AllBeItMine]

i wouldn't have thought it would have made bugger all difference.

those ultra-high compression engines or something?

meh - shows you what i know... :scholar:

at 1.41 per litre i reckon those buggers at mobil can keep their 8000...

[Kenneth]

i wouldn't have thought it would have made bugger all difference.

those ultra-high compression engines or something?

meh - shows you what i know... :scholar:

at 1.41 per litre i reckon those buggers at mobil can keep their 8000...

12.5:1 Compression ratio. Don't forget that they are a lean-burn engine also, so need high octane is a must.

[Kenneth]

GDI is apparently supposed to run with an Air/Fuel ratio of 40:1 at idle

[Smokinmasta2]

i wouldn't have thought it would have made bugger all difference.

those ultra-high compression engines or something?

meh - shows you what i know... :scholar:

at 1.41 per litre i reckon those buggers at mobil can keep their 8000...


Are you saying you only pay $1.41 per liter for that??

If so think yourself lucky m8 - WE HAVE to pay anything up to $2.40 for std unleaded or UPTO $2.50 for 98 optimax!!!


Smokin............

[pezza]

On a similarish theme....

I was wondering about this ECU reset and this power cut depending on fuel used....

How noticeable is the difference.... I have been switching tween fuels and resetting the ECU to see how much of a difference it makes and it does not seem that noticeable? Maybe I am not disconnecting the power for long enough to clear the ECU?

Additionally have just been using the G-Tech to measure times and there is hardly any difference (and still not broken the magic 6 sec barrier
:greedy: /wall ) This is with boost at 0.9... maybe me car is on its last legs reaching 120K miles???

WODJ that 5.18 is plain :rolleyes4 :drummer:

Hmm I will investigate some more.. :huh:

[i3ooyah]

i wouldn't have thought it would have made bugger all difference.

those ultra-high compression engines or something?

meh - shows you what i know... :scholar:

at 1.41 per litre i reckon those buggers at mobil can keep their 8000...

ggeeezzusss is that the price now, havnt drive the car in so long i havnt needed to use 98

good ol toyota is saving me $35 a week in gas

[aaron68nz]

at 1.41 per litre i reckon those buggers at mobil can keep their 8000...


It's about the same here in Australia after currency conversion.

Finally picked up my VR4 last Tuesday from shippers. 2 and a half months later leaving it in NZ and was surprised how much 98 was here when filled it up.

[KiwiTT]

How noticeable is the difference.... I have been switching tween fuels and resetting the ECU to see how much of a difference it makes and it does not seem that noticeable?

It will only make a difference if there is a significant change in Octane Rating.

91 to 96 is big , however, 96 to 98 is not. There will be some tolerances in the ECU, so you wouldn't notice any difference in the later, but very likely in the former. Remember the VR-4 is designed for 100 octane (as is the GDI engined cars), so the higher the octane the better.