91Ron, 95 Or 98Ron?

[PN-Mad]

9.8:1 says google for e85.

Vq35 stock ecu and add/ subtract 25% fuel, sadly I know from experience.

So, if it had an infinite range, on e85 it would still be able to trim fuel to lambda, the sensor would output volts that the ecu sees as 14.7, and the real afr would be 9.8:1?

[sonicii]

octane is octane. it's a way of measuring any fuel. LPG has an octane rating too.

Indeed!! Many people think octane or RON is some sort of fuel quality figure or fuel energy density figure.

It is not, it is just an indication of the fuel's resistance to detonation.

Both LPG and E85, have octane ratings above 100, but they return reduced fuel economy.

Edited February 11, 2014 by sonicii

[sonicii]

9.8:1 says google for e85.

Vq35 stock ecu and add/ subtract 25% fuel, sadly I know from experience.

So, if it had an infinite range, on e85 it would still be able to trim fuel to lambda, the sensor would output volts that the ecu sees as 14.7, and the real afr would be 9.8:1?

If the ECU were able to adjust, would the stock injectors be able to keep up with 33% increse in fuel demand?

[PN-Mad]

You'd have to look at the figures.

I'd say they would be marginal, not much head room.

[colin.ssc]

I've tested BP98 Vpower Caltex98 and United P100...from my experience, BP98 works best with better fuel economy than Vpower and Caltex.

BP98 vs P100...not really noticeable but I "feel" that P100 gives me more pull. Economy wise...slightly more with P100 but could just be road conditions..Nowadays I only use BP98 or P100 depending which days I need to get petrol as P100 is usually cheaper.

[scotty nm35]

Did you reset the ecu to clear the long term fuel trims though Colin? Not a good indication if you are just changing for one tank full, plus the fuels would be mixed as the tank wasn't empty.

I would expect less K's to a tank with any e10, there is slightly less energy density.

[colin.ssc]

Hey Scott, I do at least 3-4 full tanks and average it out, and then reset ecu for the new fuel and repeat.

Both my V36 and R34 does better with BP98 as well over the Caltex and VPower...

P100, pulls better and does similar K's to BP98 or just a bit more.

Actually thinking about it, P100 pulls better over Caltex and VPower....comparing to BP maybe same or so...that one I am not too sure considering I use either one.

Recently though I got my V36 tuned with P100 in it...

Do you think mixing BP98 and P100 would be a problem?

Edited February 11, 2014 by colin.ssc

[ARTZ]

Pretty sure your car would spontaneously Combust if you mixed them

[scotty nm35]

Lol

Artz mixes 98 and e85 all the time. I on the other hand have been using e85 for 5 years straight.

[PN-Mad]

Pretty sure your car would spontaneously Combust if you mixed them

Only if it was a 458...

[colin.ssc]

Lol...e85 would require change of internals wouldn't it? Don't think I wanna go down that path just yet unless I run a TT or SC on the car.

[scotty nm35]

No, any car can run on ethanol if you have enough overhead on the injectors, or just stick 30% larger injectors in and let the stock ecu work it out.

[ARTZ]

No, any car can run on ethanol if you have enough overhead on the injectors, or just stick 30% larger injectors in and let the stock ecu work it out.

this advice really should come with a disclaimer...*results may vary*

[ARTZ]

Lol

Artz mixes 98 and e85 all the time. I on the other hand have been using e85 for 5 years straight.

*results do vary*

[scotty nm35]

this advice really should come with a disclaimer...*results may vary*

Agreed, if people didn't realise, injector overhead requires you have some form of injector control, eg Osirus cable for the V35.

[The Max]

The way I see it, Ithought these vehicles were made ideally for 98RON. Why skimp on the fuel in the first place?

[The Max]

So, if it had an infinite range, on e85 it would still be able to trim fuel to lambda, the sensor would output volts that the ecu sees as 14.7, and the real afr would be 9.8:1?

As I learned in the MoTeC training seminar back in 2004, they use lambda in their ECU software because it's a universal representation of the stoichiometry as opposed to having to remember all the different AFRs for different fuels.

Therefore, a lambda of 1 in an ECU map will translate to the respective stoichiometric AFR for whatever fuel you are using.

That said, not all wideband O2 sensors back then were fit for all fuels, so there were different sensors to suit different fuels. Changing the fuel type meant changing the sensor too.

I'm not sure if that is still the case today.

As far as I can see in the UpRev Osiris software, of what little I've looked at so far, they map in AFR terms.

[Edit: Actually, I think there is a choice for AFR or lambda in the software's preferences for units of measurement. Just looked it up but couldn't confirm since I'm overseas without my Osiris cable!]

Edited February 11, 2014 by The Max

[ARTZ]

95-98 ..is there really that much difference? if i can get 95 octane e10 for 1.30$ a litre when 98 is a 1.60 a litre...thats at least a 15$ saving on a full tank of fuel...if i am using a tank a week thats maybe an 800$ a year saving...thats my registration paid....add to that ethanol will help clean your fuel system as well as any additives they put in 98....I don't see the problem except maybe 2kws and a bit less range..and i dont use 15$ worth of fuel in 50kms...

if e10 was the only fuel at the pump, everyone would run it ..but people like choices, this is the MAIN reason we have different fuels...if water was the only drink in the fridge, you would happily drink it but no, go to a servo and there is 4572 different drinks to choose from...why? because peopel like choice...truth is it really makes no difference what pump fuel you run because your car was built for its tolerances in mind......true some fuel might make your car live a little longer, but alot of people couldn't care care less...cars are disposable...

The way I see it, Ithought these vehicles were made ideally for 98RON. Why skimp on the fuel in the first place?

people like choice

end

[The Max]

95-98 ..is there really that much difference? if i can get 95 octane e10 for 1.30$ a litre when 98 is a 1.60 a litre...thats at least a 15$ saving on a full tank of fuel...add to that ethanol will help clean your fuel system as well as any additives they put in 98....I don't see the problem except maybe 2kws and a bit less range..and i dont use 15$ worth of fuel in 50kms...

if e10 was the only fuel at the pump, everyone would run it ..but people like choices, this is the MAIN reason we have different fuels...if water was the only drink in the fridge, you would happily drink it but no, go to a servo and there is 4572 different drinks to choose from...why? because peopel like choice...truth is it really makes no difference what pump fuel you run because your car was built for its tolerances in mind......just like it doesnt matter what drink you choose from the fridge its going to kill you anyway..

people like choice

Water is better for me than any other beverage. It's not really a fair comparison. Using 95RON as opposed to 98RON isn't recommended for the vehicle and it has nothing to do with choice. I can also choose to scratch my crotch with a cheese grater, or perhaps less severely, wash my car with a scouring pad but that doesn't make any of it a wise choice. You put in what it needs, not what you choose.

A Toyota Yaris is made for 91RON so with the possible exception of slightly better fuel economy (though I wouldn't know for a fact), there'd be no benefit for 98RON.

A V36, on the other hand, is made for 98RON so running 91RON would simply be deemed inappropriate.

The choice we're given is what car we choose to drive and in turn what support we get at the bowser. There's not much choice with the fuel, from my point of view.

Edited February 11, 2014 by The Max

[ARTZ]

Does it say in the owners manual ...use 98RON...if so then there is the answer to OPs question....

Does it matter if he chooses to put e10 in it everyday instead of 98?...No, not one bit....