will 95 octane petrol really do damage to my j-spec engine???

[supra-lover]

As was mentioned earlier, the NA will be fine on the 95 Octane. I believe the TT should be run on the higher octane due to my post above.

 

well if you say it's o.k... I'M GONNA STAND BY YOU MY DEAR FRIEND:)

[RedM]

What sort of petrol was available in Japan when the mkiv came out in 93?

[letmeshowyou]

I always found using 95 was a false economy in my N/A as I saw a higher mpg with Super unleaded!

[CJ]

What sort of petrol was available in Japan when the mkiv came out in 93?

100 octane

[stupra]

If nothing else was available, an you needed fuel real bad, a few quid of 95 ron would have to be ok, even in a TT, (not that i'd be happy doing it). As long as you drove it gently, it wouldn't cause it any harm would it ?.

[Bob]

I've been forced to use 95RON in my stock TT several times. I've always driven it fairly gently until I can fill up with Optimax / Ultimate / etc. but I've never had a single problem. Wouldn't the lower octane simply mean a stronger chance of detonation when the engine is being thrashed?

[stupra]

Wouldn't the lower octane simply mean a stronger chance of detonation when the engine is being thrashed?

 

Thats what I was thinking. TDI once told me that the soop is in quite a lazy state of tune out of the factory, an that unlike the jap spec scoobie's an evo's, which see quite a big gain, the soop doesn't gain much, an doesn't need re mapping for our fuel, (97-98 ron). I'll still take it easy if I ever get stuck an have to use the 95 ron stuff. Makes you wonder though, is the higher ron fuel more expensive to make ?, or do they know that us performance car drivers will buy it, an so whack a bit more money onto the forecourt prices ?.

[RedM]

Makes you wonder though, is the higher ron fuel more expensive to make ?, or do they know that us performance car drivers will buy it, an so whack a bit more money onto the forecourt prices ?.

 

Of course they whack the price up. It's Pointy Nose Syndrome. People who drive cars with pointy noses can afford to pay extra for everything.

[Rich]

They program the EMS to run with the higher octane fuel that is readily available in Japan.

[Whitesupraboy2]

the guy before me had the NA for 6 yrs and ran it on 95 ron, i had it for 3 yrs and ran it on 95 ron.....in other words its safe to run a NA on 95 ron.

[montezumola]

So in conclusion is it safe to say:

 

N/A - use 95 ron

Stock TT - 95 ron okay, but preferably 97/98 ron

BPU TT - 97 - 99 ron

Singles - 98 - 102 ron

 

???

[Rob Dublin]

I always found using 95 was a false economy in my N/A as I saw a higher mpg with Super unleaded!

 

 

In my N/A I find that for 4-5% cost increase, I get 10-15% further mileage wise. Car also seems to pull a lot better, so it's cheaper and faster.

When I 1st joined I asked this question. Do a search for "octane", there should be a couple of other threads on here on the topic.

[Rob Dublin]

So in conclusion is it safe to say:

N/A - use 95 ron

???

 

I definately wouldn't agree with that, 97 or higher is better.

[RiceRocket]

Can the ECU on any Supra model determine the octane rating of the petrol being chucked in?

I know modern performance cars such as the Golf GTI can and it thus advances the ignition timing for more power and torque for higher octane stuff.

Also petrol like Ultimate and Optimax are more expensive because they contain additives and other lovely chemicals that normal petrol doesn't have.

[stevie_b]

I think high octane fuel may be more refined, hence more expensive. Most NA owners on here (including me) run their soop on 95 RON. Most TT owners run theirs on 97 RON or higher.

[Shilakadaddy]

I always use the higher octane stuff anyway because it only works out around £100 more per year to use that over the normal stuff (not a huge amount when considering you probably spend around £2000 on fuel anyway)

[Nic]

If you are changing your fuel to 95 ron, I would reset the ECU at the same time so it can relearn the settings. Once reset it may not idle well at first but should be fine afer a couple of miles driving.

[montezumola]

Isn't 95 Ron petrol considered super-high octane over in the States?!

[lust2luv]

Yes, because quoted octane ratings in the US are RON+MON/2, so 95 octane would be a super high quality fuel. Options there are usually 87 / 89 / 91, with some places selling 93. I think fuels here are typically around 85 MON (which in many ways is a more important factor than a fuels RON), so Tescos 99 RON would be 92 octane in the US, super unleaded would be 91.

 

Personally I've always ran my NA on Optimax.

 

[Geo]

I will be getting my j-spec TT very soon off Jurgen very soon. The thing is where i live there is a lack of Shell/BP/ garages that sell Optimax etc. Iv just got Morrisons and Tesco that sell the super unleaded or 95ron, will these be ok to use then? And then fill up with opitmax when i get the chance?

[KaoriFan]

sincei got my Supra TT in Oct 2005, i so far have nearly always used Esso 97 ron super-unleaded, as i can't get anything else here, unless i want to brave the back of Hastings.

 

nearest place for me, is on the A21 for the good stuff, and a decent place to fill-up.

[twijesiri]

I Think you may have a point.

 

I was always told to use 99 ron on my N/A '93, but I think I will try, my-be half a tank on the regular stuff and see. The car its self only has an induction kit and exhaust and is not heavily modded.

 

So I think, with all the positive feedback on 95ron fuel I will give it a go.

[RiceRocket]

if you want more octane, buy some octane booster stuff like Millers etc

[Thorin]

if you want more octane, buy some octane booster stuff like Millers etc

 

I'd forget all that rubbish. Buy some Toluene, even works out cheaper per gallon than petrol.

[Lucifer]

I'd forget all that rubbish. Buy some Toluene, even works out cheaper per gallon than petrol.

 

Stand well back!