[Mk2] [Turbo] STANDARD UNLEADED OR SUPER???

[russo]

Have owned an MR2 turbo now for 3 years. Just read a thread which suggested turbos MUST be fed with superunleaded petrol. Is this correct or not?

[Ryan S]

Have owned an MR2 turbo now for 3 years. Just read a thread which suggested turbos MUST be fed with superunleaded petrol. Is this correct or not?

yeah it's correct, they are set up in japan to run on higher RON petrol, 99 i think, which is the same as v-power etc over here, they do run on normal unleaded but i've heard it's not good for them, although i don't know what we did before the v-power/bp ultimate stuff was around, i doubt that everyboday added the additive stuff in everytime they put fuel in.

[bri0905]

Shell have been selling 98ron fuel for years. Was called optimax then got re branded to V Power. Not sure when it became available but i've used it since about 2000.

[RobCrezz]

Yes, same goes for more or less every turbo car imported from Japan (Impreza, evo etc)

[Tiny]

must be run on 98+ ron avoid anything 97 or below mine doesnt like 97 and have never run on 95 without an additive even then thats a last resort.

unless your car is specifically mapped for 95 then its got to be super

I would recomend V power (99.6) or Tesco(99.4) or BP(98.7).

[boosch]

as I understand it, the higher the RON, the less likely the car is to detonate (this is combustion happening when it shouldnt!). Higher RON figure is smoother more predictable combustion, lower ron is shoddy all over the place explosions new pistons and cylinders please, sorry officer it was like that when I got here, dont know whose car it is, whats that dave? I'll be right there, gotta shoot, Bye....sort of situation.

V power, or Tescos rocket fuel.

97 or 95 if you have a pregnant lady ready to pop a sprog and you run out of fuel and its the only fuel available, and then avoid the boost. or deliver the baby at the fuel station.

[Marf]

Yes, run your tubby on V-Power or Tesco 99.

If you have been running normal super and are going to switch to V-Power/T99 then reset your ECU at the same time, as doubtless the ECU will have pulled timing to compensate for the lower grade fuel that you've been feeding the engine.

Shell have been selling 98ron fuel for years. Was called optimax then got re branded to V Power. Not sure when it became available but i've used it since about 2000.

It wasnt just a rebrand, V-Power is a different product. Its 99 octane compared to Optimax which was 98.

[reecep]

sorry for hijacking but Tesco Super unleaded is that the 99ron version or is that 97ron and there is another type that is 99ron. just asking as i keep hearing about it but all the Tesco's near me are labelled Super Unleaded 97??

[raptor95GTS]

sorry for hijacking but Tesco Super unleaded is that the 99ron version or is that 97ron and there is another type that is 99ron. just asking as i keep hearing about it but all the Tesco's near me are labelled Super Unleaded 97??

not all Tesco's supply 99, hence the 97 stuff.

[Marf]

sorry for hijacking but Tesco Super unleaded is that the 99ron version or is that 97ron and there is another type that is 99ron. just asking as i keep hearing about it but all the Tesco's near me are labelled Super Unleaded 97??

not all Tesco's supply 99, hence the 97 stuff.

Yup depends if they are reselling Esso petrol or supplying their own.

If they are reselling Esso its 97.

http://www.greenergy.com/tesco_99_octan ... o_buy.html

[reecep]

seems they sell it everywhere but Leicestershire d'oh!!

[boosch]

seems they sell it everywhere but Leicestershire d'oh!!

and Cornwall! its not even on their list of counties!

[Jaspa]

and Cornwall! its not even on their list of counties!

They're always campaigning for their independence. Guess someone listened

[mattcambs]

Have owned an MR2 turbo now for 3 years. Just read a thread which suggested turbos MUST be fed with superunleaded petrol. Is this correct or not?

Welcome to IMOC How come it took you 3 years? [wondering why no-one advised you to use the correct fuel ]

Do you have a rev3 (1994 onwards)? If so, you've probably being getting away with using 95RON because the ECU will protect the engine if too much knock is detected. You'll make less power than is possible, though.

[Jim Galbally]

AFAIK the MR2 ECU does not have active knock control so running it on xxxx fuel will normally end in distaster.

why you think there are so many jap import scoobies blown up and people blaming chocolate engines when it's doen to owner stupidity

the stickers all over the petrol cap were the give away what fuel to put in it... lol

[mattcambs]

AFAIK the MR2 ECU does not have active knock control so running it on xxxx fuel will normally end in distaster.

It won't end in disaster. If the ECU detects serious enough knock then it will go into safe mode. An ECU reset will then be needed I believe.

AFAIK rev3 onward ECUs are far more tolerant of lower RON fuels in their mapping and so it may well be possible to get away with 95RON without too much knock.

Be good to hear back from the OP

[Jim Galbally]

thats not how active knock control works.

there will be a knock sensor which is a crude mechanical device that detects certain frequencies, these will be the frequencies that occur most during det. firstly, these sensors aren't great, no knock sensor is 100% reliable.

anyway, depending on the ECU, when the ECU detects knock it will do one of 2 things, the least common is enter LOS (limited operational strategy) aka safe mode/limp home mode. very few ECUs do this, none i kow of on performance turbo cars.

the most common is it will retard the ignition timing until knock no longer occurs.

few things to take note of

*at the best of times this method is unreliable
*at the worse it just doesnt work
*if the ECU doesnt have it in the first place (which i dont THINK rev1/2 does) it's totally irrelevant

[mattcambs]

thats not how active knock control works.

there will be a knock sensor which is a crude mechanical device that detects certain frequencies, these will be the frequencies that occur most during det. firstly, these sensors aren't great, no knock sensor is 100% reliable.

anyway, depending on the ECU, when the ECU detects knock it will do one of 2 things, the least common is enter LOS (limited operational strategy) aka safe mode/limp home mode. very few ECUs do this, none i kow of on performance turbo cars.

the most common is it will retard the ignition timing until knock no longer occurs.

few things to take note of

*at the best of times this method is unreliable
*at the worse it just doesnt work
*if the ECU doesnt have it in the first place (which i dont THINK rev1/2 does) it's totally irrelevant

Good info

Basically, always use Super Unleaded (99RON where possible)

[Lou-Lou]

I always ran mine on 97 with the occasional tank of V-Power.

Never had any problems with it.

Same with my current s14..

[steve b]

thats not how active knock control works.

there will be a knock sensor which is a crude mechanical device that detects certain frequencies, these will be the frequencies that occur most during det. firstly, these sensors aren't great, no knock sensor is 100% reliable.

anyway, depending on the ECU, when the ECU detects knock it will do one of 2 things, the least common is enter LOS (limited operational strategy) aka safe mode/limp home mode. very few ECUs do this, none i kow of on performance turbo cars.

the most common is it will retard the ignition timing until knock no longer occurs.

few things to take note of

*at the best of times this method is unreliable
*at the worse it just doesnt work
*if the ECU doesnt have it in the first place (which i dont THINK rev1/2 does) it's totally irrelevant

All MR2 turbos have knock sensors

Rev 1 & 2's when run on 95 ron go into safe mode, boost is dropped and timing pulled, the car turns into a real slug.

rev3+ cars I've not owned, but from all i've read have more comprehensive map and timing is pulled back.

What neither car will do is re-advance ignition, you have to reset the ECU to get it back to how it should be.