in my mr-s should i be using normal unleaded or super different people have told me different? (mght be a silly question but im blonde lol)
i'm not the most experienced around here, but if your '2 is totally stock as far as the engine goes, i'd suggest regular unleaded, as I think you need to advance the ignition timings a bit to take advantage of the higher octane...
yeah i have always used regular unleaded as thats what the prev owner used, few people told me that the car would benefit if i used super, lol im doing an engineering degree but i dont no! someone also said because its an import i should use super as in japan they have a higher ron petrol
I wouldn't have thought it would make much difference to a standard engine (it's not a Ferrari after all is it ?!), but as Shell Optimax is only about 4p a litre more than unleaded round my way I use it anyway.
Just make sure you don't use that supermarket cr@p !
my step dad has an evo8 and they swear by the super markey super unleaded its apprently the best out there
wen im feeling rich and want to treat my car i fill her up with bp ultimate
Supermarket fuel is cheaper because they don't put (as many) detergents in. Check this site out also
w www.petrolprices.com (http://www.petrolprices.com) w
If you look around the cheapest branded petrol is only a penny more than the supermarkets.
Depends what supermarket fuel you're using.
I'm using Tesco 99RON in mine with the turbo conversion and that does have additives -
m http://www.greenergy.com/products/99_octane.html (http://www.greenergy.com/products/99_octane.html) m
Its higher octane as well as being a few pence cheaper the Optimax near me s:) :) s:)
I think (trying to remember an old post) that for the UK cars at least, there is no benefit to using higher octane fuels. I'm not sure if the mr-s is the same though.
I've used Optimax a couple of times and haven't noticed any difference.
On my previous car (modified 405) I ran it on Optimax because there was a noticeable difference if I used normal unleaded instead.
Jason
Its about what its mapped for.
My Jap import MR2 Turbo beast was mapped for 100 ron so it can make use of it. And in that car adding normal fuel even causes the car to go into safety mode and limit power etc.
I guess you can map a normal na for the higher octane fuel, although without the map I think the extra is just lost in pinking (is that right?)
I will still pop in the odd tank of optimax to clean things through in my roadster in case of any benefit due to removing buildups. Tho that may be a myth i suppose.
Phil
Does the MR2 have a knock sensor, if so that will automatically adjust to what octane of fuel is in the tank?
I ran mine on Optimax all the time in anycase out of choice, but had to after the Unichip was fitted, it also gave better fuel economy. Since having the Porker I have tried many different types of fuel but can confirm that I get better economy (28-29 mpg) using the better performance fuels mainly Optimax and I am in the process of trying BP Ultimate now, I tried Tesco 99 but fuel economy was worse and it didn't feel so responsive. Matter of trying out and seeing what your pocket and the car prefer.
cheers for your help, mite try the 99 ron stuff to see,
Quote from: "Liz"Does the MR2 have a knock sensor, if so that will automatically adjust to what octane of fuel is in the tank?
Yes, I believe it does, and the ECU is able to adjust timing depending on detonation that it picks up.
However, I did have mine on a Rolling road Pre-Turbo conversion and it was producing close to a book 136.5 bhp with Optimax - I'd have expected it to make at most just a few BHP difference on a normally aspirated setup, this tends to indicate the ECU doesn't make best use of Higher RON fuel.
Quote from: "Liz"Does the MR2 have a knock sensor, if so that will automatically adjust to what octane of fuel is in the tank?
Yep, it does have a knock sensor.
It's more than just down to that, though. It depends on how the ECU is mapped & written by Toyota. Essentially, they can go one of two ways (most 'economy' cars go the former, 'performance' cars seem to go the latter, recently):
Map for the lowest common octane rating, and use the knock sensor only to further retard timing if something is going wrong (water in the fuel, oil ingestion and soforth). This way, you'll see little, if any, performance increase in using higher octane fuel - unless you were seeing excessive knock to start off with.
Map for the highest available octane rating, and use the knock sensor to pull timing in all but 'perfect' conditions. This way, you'll get a good bump in power by switching to higher octane fuels, since the ECU will be able to go back to running full advance (or closer to full advance).
I'm not sure which ours is, really.. empirical evidence suggests the latter (people report better response on Optimax etc), but my gut feel is that it's the former (since, in reality, our car has a grocery-getter economy engine in it).
Remember the test done on the Gadget Show - a supermini (Clio) saw no increase in power on Optimax (or 1-2bhp, so it's ECU is mapped for low-octane economy fuel, and only uses the knock sensor in an emergency), while the Golf GTI saw a healthy (9-10bhp) increase, suggesting it's ECU is mapped for high octane fuel, and it uses the knock sensor to pull timing out when running on lower fuel ratings.
Different to Japanese import turbocharged cars, which are usually mapped for 100RON Japanese fuel, as they were imported to the UK as more of an 'afterthought' than a design consideration.
[edit] Damn you Ben s;) ;) s;) I swear when I started this reply, yours wasn't there s:lol: :lol: s:lol: [/edit] s:) :) s:)
Got 140hp with 95 octane and with 98+ octane:
m http://koti.mbnet.fi/temmeke/tmp/dyno.jpg (http://koti.mbnet.fi/temmeke/tmp/dyno.jpg) m
There was a year or so between the runs, so there might be other things affecting it, but I know I've kept using the 98+ since.
Quote from: "BenF"Depends what supermarket fuel you're using.
I'm using Tesco 99RON in mine with the turbo conversion and that does have additives -
m http://www.greenergy.com/products/99_octane.html (http://www.greenergy.com/products/99_octane.html) m
Its higher octane as well as being a few pence cheaper the Optimax near me s:) :) s:)
I used the Tesco 99Ron Super and have been happy with it
Does a turbo generally require 98 RON or can they run on 95? Or does it vary?
typicaly super unleaded only in my experience.
With most things in general its about what the car is mapped for.
98 RON is very hard to get in Ireland for very stupid reasons.
Could you map the turbo for 95 without ill effects?
Yep, although you'd obviously be down on power than a car mapped to 98.
I'm using Tesco 99 ron in the turbo, and its running very nice s:D :D s:D
just for reference the knock sensor is located n the left side of the block at the top