My daily driver fuel question

Habanero666 · Post by **Habanero666** » Fri Nov 20, 2009 9:33 pm

I use shell premium and 15% toulene. Keeps that nasty pinking away at 7200rpm+ 17psi

poison · Post by **poison** » Sat Nov 21, 2009 12:33 am

From Wiki

In Australia, toluene has been found to have been illegally combined with
petrol in fuel outlets for sale as standard vehicular fuel. Toluene attracts
no fuel excise, while other fuels are taxed at over 40%, so fuel suppliers
are able to profit from substituting the cheaper toluene for petrol. This
substitution is likely to affect engine performance and result in additional
wear and tear. The extent of toluene substitution has not been determined.

And you thought diesel was bad....
http://en.wikipedia.org/wiki/Toluene_(toxicology)

Timmo · Post by **Timmo** » Sat Nov 21, 2009 8:00 am

I used BP when I've owned turbo cars in the past (Soarer, MR2) in order to get BP ultimate.

Now I use Caltex- 96 is fine for an NA8....putting 98 octane in is overkill- The engine simply won't put the fuel into a state where the extra anti-knock properties will be useful.

Ian · Post by **Ian** » Sat Nov 21, 2009 9:36 am

Quidam wrote:This is all good stuff, and definately shows up my ignorance on this subject.

Speaking of ignorance, I normally buy from Caltex, the techron engine cleaning marketing thingy made me think it was agood fuel choice -but isn't the best they offer 95? Should I be going to PB instead?

To the best of my knowledge, Mobil 98 is only available in the North Island, and even Nelson (last time I looked) had no BP 98!! These are the only 2 with fuel companies with 98 in the country that I am aware of, but could be wrong.
I run my MX5 on BP98 as I have advanced timing and as a safeguard when competing. NZ new cars (NA 1.

are recommended to run on 91 and there is nothing to be gained by running on anything higher if the car is stock standard and in good condition. (the 93 1.8 had a CR of nominally 9:1, but actually 8.9:1). A friend who has built many a high performance motor incl NZ V8s recommeneds 95 as a minimum for all cars which can use 91, to safeguard against 'dodgy' batches of 91.
As already mentioned, some modern cars ECU's have the ability to 'read' fuel octance and make most HP on higher octane fuel...up to a point. (A read thru a BMW handbook makes interesting reading on this subject). But others do not, incl my MX5, so it is because of manufacturers engine design/factory settings, engine modifications and/or competition that high octane can be justified. (I believe a heavily carboned cylinder head may have a taste for higher octane as well.......)
At least, this is my understanding on the matter.
Cheers

Habanero666 · Post by **Habanero666** » Sat Nov 21, 2009 10:55 am

poison wrote:From Wiki

In Australia, toluene has been found to have been illegally combined with
petrol in fuel outlets for sale as standard vehicular fuel. Toluene attracts
no fuel excise, while other fuels are taxed at over 40%, so fuel suppliers
are able to profit from substituting the cheaper toluene for petrol. This
substitution is likely to affect engine performance and result in additional
wear and tear. The extent of toluene substitution has not been determined.

And you thought diesel was bad....
http://en.wikipedia.org/wiki/Toluene_(toxicology)

[Posted via external email]

Hey there Poison, cheers for that. Yes I have been aware of the human bodies difficulties metabolizing toluene (all petrol contains a component of this hydrocarbon if I am correct).

1980's Formula 1 engines used large amounts to prevent knock from there 4 Bar boosted 1.5L turbo donks.
They also had to drain the fuel system clear of the fuel after each session so that there is an engine left the next morning!

I wear gloves when handling any solvent, also a cool mask and protective glasses!

My Stuff burns better than 98RON pump fuel, I have not encountered preignition or atomisation problems with a 9.4:1 static CPR off cam, off boost@ atmo air temp 4-28*C, 550cc injectors or ~ 17psi boosted intake air temps +15*C above ambient ( recorded atmo of 23*C), on cam >4500rpm.

Of coarse, this fuel is only for off road use.

So any way, in the metabolism of toluene, 95% is oxidized to become benzyl alcohol*.The toxic metabolites are created by the remaining 5% that are oxidized to benzaldehyde and cresols. Most of the reactive products are detoxified by conjugation to glutathione but the remainder may severely damage cells!

Modern pump gas contains ~10% of these aromatics (makes the fuel smell nice), toluene being a percentage of these bad boys.

*Benzyl alcohol is a common preservitive used in medicines and cosmetics, but benzaldehyde..... Requires protective handling equipment!
and has no place in the human body.

Quidam · Post by **Quidam** » Sat Nov 21, 2009 12:50 pm

Jesus Habanero are you a chemist or something

Quidam · Post by **Quidam** » Sat Nov 21, 2009 12:54 pm

Ian wrote:To the best of my knowledge, Mobil 98 is only available in the North Island, and even Nelson (last time I looked) had no BP 98!! These are the only 2 with fuel companies with 98 in the country that I am aware of, but could be wrong.
I run my MX5 on BP98 as I have advanced timing and as a safeguard when competing. NZ new cars (NA 1. are recommended to run on 91 and there is nothing to be gained by running on anything higher if the car is stock standard and in good condition. (the 93 1.8 had a CR of nominally 9:1, but actually 8.9:1). A friend who has built many a high performance motor incl NZ V8s recommeneds 95 as a minimum for all cars which can use 91, to safeguard against 'dodgy' batches of 91.
As already mentioned, some modern cars ECU's have the ability to 'read' fuel octance and make most HP on higher octane fuel...up to a point. (A read thru a BMW handbook makes interesting reading on this subject). But others do not, incl my MX5, so it is because of manufacturers engine design/factory settings, engine modifications and/or competition that high octane can be justified. (I believe a heavily carboned cylinder head may have a taste for higher octane as well.......)
At least, this is my understanding on the matter.
Cheers

Nice write up Ian, and unlike Habanero's post I actually understood most of it

Anyway, It's back to BP for me (used to go with them before I switched to Caltex, but with 2 turbos now in my garage it's top shelf all the way -based on everything I've read so far)

Stevo · Post by **Stevo** » Sat Nov 21, 2009 5:09 pm

I have been told that later model cars adjust the ecu to run on the gas thats been pumped in. ie if it can run on 91, you can put in 95 or 98 and the ecu will automatically re-tune the engine to suit the new ron rating.
If you have 1/2 a tank of 91 and top it up with 95, it will re-tune to 93.
I'm not sure if this is the case with the MX5 but I must admit that mine gets filled with 91, 95 or 98, depending on what I intend to use it for and how financial I am at filling time. I use 95 more than the others.
I have found very little difference in performance between all fuels.
Cheers Stevo

Mark · Post by **Mark** » Sat Nov 21, 2009 6:29 pm

Habanero666 wrote: Modern pump gas contains ~10% of these aromatics (makes the fuel smell nice), toluene being a percentage of these bad boys.

It wouldn't surprise me if the volume is much higher than 10%.
Perhaps others recall Shell (perhaps another company) marketing petrol in NZ with "the power of methylbenzene". (Toluene is methylbenzene) in the late '60s to '70s?
To make petrol from crude, and to maximise yield of high value end-product, they use "cracking" (hydrocracking) to split the heavy fractions, and "reforming" to combine the light fractions. The mix they end up with for petrol, perhaps once long ago originally alkanes (octane, heptane etc) when distilled from crude, is now a blend of all sorts of things. One process they use is "platforming" (a reforming process) to make "BTX". The "T" in BTX" is Toluene. Another octane booster (excluding use of alcohol) is MTBE, but AFAIK, it's a more expensive process, and platforming increases yield from the refinery, perhaps especially in a country like NZ where light alkenes etc aren't used locally for making plastics (polyethylene etc - there's no plant here, but they are commonly next door to, or included in refineries overseas).

When NZ switched to high octane lead-free, levels of BTX were very high, and the high solvent power of these aromatics caused some problems with carbs and fuel lines etc in some cars. The aromatic level was I believe reduced, probably though importing MTBE, but there are still aromatics in fuel, and probably more the higher the octane rating.

All good so far, "the "T" in BTX is toluene, the "X" is Xylenes (isomers of dimethylbenzene) both commonly used solvents in industry, and as pointed out in the thread above, with some definite hazards. But nothing compared to the "B" - which is Benzene, and is present in NZ fuels in significant quantity. The more "BTX" the more Benzene will be present. Benzene has long been known as a carcinogen, in particular it causes leukaemia (but not limited to that). There are epidemiological studies overseas showing incidence of chilhood leukaemia correlating with proximity to petrol stations. Because lead stops catalytic converters working, catalytic converters could now be used with regular and high octane fuels. This is good because of reduction of NOx and other nasties from the exhaust, including incompletely combusted hydrocarbons. But also, there's significant quantities of benzene in the exhaust fumes, if the catalytic converter isn't working (or when it's cold). So there have been plenty of cars with no CC, a "dead" CC from use with old leaded fuel, or removed CC for performance, and over a time period when BTX levels in NZ petrol were high.

In the US and part of Europe, perhaps elsewhere, the level of Benzene in petrol is not allowed to be over 1%. I think it's supposed to be being reduced to the same 1% level here, but it has been much higher.

It would be interesting to know benzene levels at a typical gas station forecourt in NZ. Over 1 part per million is a problem.

The history of main world maker of Tetraethyl lead (Ethyl Corp) makes interesting reading, how the danger of lead was misrepresented for decades, how the fuel industry and governments ignored what was going on, scandalous at a scale comparable or even worse perhaps than the tobacco industry.

But now that lead is gone, don't think petrol is safe. It wouldn't be legal to sell paint or paint thinner with as high level of benzene as petrol. The safety warnings would include a very big label to say that it is a known carcinogen.
I used to use Benzene in laboratory analysis - even 30 years ago, I would don protective clothing, and not open the 500 ml bottle until it was in a ventilated fume cabinet with filtered exhaust outside.

Gravelben · Post by **Gravelben** » Mon Nov 23, 2009 10:03 pm

Ian wrote: To the best of my knowledge, Mobil 98 is only available in the North Island, and even Nelson (last time I looked) had no BP 98!! These are the only 2 with fuel companies with 98 in the country that I am aware of, but could be wrong.

As far as I've found you can't get BP 98 anywhere south of Dunedin either! Its a bugger when you're living in Southland with a twin-turbo Legacy, I've been adding octane boost to 95 to play it safe which does add a bit onto the fuel bill unfortunately.

I just feed the MX5 on 95, never tried 91 but not sure if 91 would still be safe with the timing at 14°. Having said that its been feeling a bit down on power since getting the cambelt done a while back, I'm wondering if they set the timing back to standard when they did it.

brownie · Post by **brownie** » Mon Nov 23, 2009 10:29 pm

For those of you who can't a decent fuel,We sell a product thru work called Redline SL170 fuel additive,We find this stuff brilliant for boosting octane and cleaning out carbon build up,You can get it at most BNT outlets for around $20-$25 ,You only put around 20mls at a time in so a 100 ml bottle so lasts quite awhile,I have sold a heap of it thru work and have custys coming back for more ,they notice there car runs better and uses less fuel.
A example of this ,A 4-5 years ago I had as a company ute a Mazda B2600 EFI D/cab petrol ute,What a pig on fuel it was too !!(200km's a tank on 91 !!),and pinked like buggery,95 fuel ,better,230km's a tank,95 and a bit of redline,NO pinking and 260km's a tank ,Still crappy mileage from a 45ltr tank but ran nicer,Works wonders in the lawn mower as well

,Swear it revs better.
Something for you guys to keep a eye out for,From my experience and feedback ,very worthwhile.

For those in the know ,what your opinion on running a bit of No 1 race fuel in with 95 pump fuel,or even Methanol,Out of curiosity ,Happen to have access to both fuels thru speedway but don't know if it would be advisable,Don't want to kill my baby

Ian · Post by **Ian** » Tue Nov 24, 2009 6:51 pm

Gravelben wrote:
Ian wrote: To the best of my knowledge, Mobil 98 is only available in the North Island, and even Nelson (last time I looked) had no BP 98!! These are the only 2 with fuel companies with 98 in the country that I am aware of, but could be wrong.
As far as I've found you can't get BP 98 anywhere south of Dunedin either! Its a bugger when you're living in Southland with a twin-turbo Legacy, I've been adding octane boost to 95 to play it safe which does add a bit onto the fuel bill unfortunately.

I just feed the MX5 on 95, never tried 91 but not sure if 91 would still be safe with the timing at 14°. Having said that its been feeling a bit down on power since getting the cambelt done a while back, I'm wondering if they set the timing back to standard when they did it.

Thanks for that (running at Teretonga Dec 5th/6th so will take some 98 from here - Q'town)
Ran a Legacy twin turbo on 96 a few yrs back with no probs.
Cheers
Ian

Gravelben · Post by **Gravelben** » Thu Nov 26, 2009 12:37 am

I don't like the lack of power with my Legacy on 95, you can really feel the ECU pulling things back. Being a 2002 its higher compression than the older ones (9.0:1 IIRC) and poking about 16psi from the factory so there is a bit of pressure happening in there.

Is the 5th/6th a race meet or trackday? If trackday I'll be keen, otherwise might come watch/snap some photos anyway. Tempted by Ruapuna playday on the 20th but its quite close to xmas.

I also realised out why my MX5 has been feeling down on power, bit of a duhh moment - I'd replaced a seized caliper a few months ago just before the waterpump went, obviously hadn't adjusted things quite right - was binding just enough to feel slow and drink more fuel without obviously getting hot. Explains why its been a bit twitchy on the brakes too, an hour tinkering tonight and its all sorted.

Habanero666 · Post by **Habanero666** » Fri Nov 27, 2009 12:21 am

Quidam wrote:Jesus Habanero are you a chemist or something

Nope, I am a Hartley!

Timmo · Post by **Timmo** » Fri Nov 27, 2009 11:33 am

Stevo wrote:I have been told that later model cars adjust the ecu to run on the gas thats been pumped in. ie if it can run on 91, you can put in 95 or 98 and the ecu will automatically re-tune the engine to suit the new ron rating.
If you have 1/2 a tank of 91 and top it up with 95, it will re-tune to 93.
I'm not sure if this is the case with the MX5 but I must admit that mine gets filled with 91, 95 or 98, depending on what I intend to use it for and how financial I am at filling time. I use 95 more than the others.
I have found very little difference in performance between all fuels.
Cheers Stevo

Yes and no- The ECU will adjust to fuel but only in a negative way- If your car has been designed to run on say, 91 RON, and you put in 98 RON, you won't suddenly get more power. The engine hasn't been set up in a way that will utilise the extra 'squeezability' that higher octane fuel allows (i.e. higher strung sports engines sometimes run higher static compressions, boost or advanced timing which squeezes the fuel/air charge. These cases requires higher octane fuel to avoid the fuel exploding due to compression before being ignited by the spark)

If, however, your car has been designed to run on 96 RON and you've been using 91, the ECU has been probably retarding timing all that time. If one then uses 96 RON fuel, the ECU is simply bumping timing (i.e. power) to where it should be....this feels like 'extra' power but is, in fact, normal power.

The engines in the MX5 are fairly tame in their standard tune. 98/BP Ultimate is overkill.

Quidam · Post by **Quidam** » Fri Nov 27, 2009 12:30 pm

Habanero666 wrote:
Quidam wrote:Jesus Habanero are you a chemist or something
Nope, I am a Hartley!

As in Formula 1 Hartley?!?

http://www.stuff.co.nz/sport/motorsport ... ivers-seat

Habanero666 · Post by **Habanero666** » Fri Nov 27, 2009 3:22 pm

Quidam wrote:
Habanero666 wrote:
Quidam wrote:Jesus Habanero are you a chemist or something
Nope, I am a Hartley!
As in Formula 1 Hartley?!?

http://www.stuff.co.nz/sport/motorsport ... ivers-seat

Hahaha! The Stig?, not me.

A few of his brothers and cousins are fast too, his Dad builds fantastic engines and a distant uncle does the best Cam grinds in this area.

Ian · Post by **Ian** » Fri Nov 27, 2009 8:14 pm

Gravelben wrote:I don't like the lack of power with my Legacy on 95, you can really feel the ECU pulling things back. Being a 2002 its higher compression than the older ones (9.0:1 IIRC) and poking about 16psi from the factory so there is a bit of pressure happening in there.

Is the 5th/6th a race meet or trackday? If trackday I'll be keen, otherwise might come watch/snap some photos anyway. Tempted by Ruapuna playday on the 20th but its quite close to xmas.

I also realised out why my MX5 has been feeling down on power, bit of a duhh moment - I'd replaced a seized caliper a few months ago just before the waterpump went, obviously hadn't adjusted things quite right - was binding just enough to feel slow and drink more fuel without obviously getting hot. Explains why its been a bit twitchy on the brakes too, an hour tinkering tonight and its all sorted.

5th/6th is a race meeting...racing on Sunday( testing Sat pm). OSCA, Pro 7/Super 6 etc etc etc. 4 races for club cars...which I am doing. First time back at Teretonga in anger for 21 yrs.........hope I can remember which way the track goes!

Quidam · Post by **Quidam** » Sat Nov 28, 2009 8:13 am

Pic of my GT4 with the new 18inch Konig Unkowns

A complete transformation compared to the 16 inch stock mags. Also makes the ride a little more firm, but still feels soft compared to my MX5, which literally rattles my teeth! (the Mazdaspeed Miata has even stiffer suspension than the regular MX5, which to be honest I think is overkill -you would never buy this car for the comfortable ride)

ps if anyone is interested/curious, this is a very good review of the MSM which covers off all the mods over the regular MX5 -it was much more than just adding a Turbo to the engine!!

http://www.modified.com/roadtests/0406s ... index.html

Gravelben · Post by **Gravelben** » Sun Nov 29, 2009 12:30 am

Ian wrote: 5th/6th is a race meeting...racing on Sunday( testing Sat pm). OSCA, Pro 7/Super 6 etc etc etc. 4 races for club cars...which I am doing. First time back at Teretonga in anger for 21 yrs.........hope I can remember which way the track goes!

Sounds fun, will try and get down for the day then. Shooting photos for the MacKenzie Car Club 40th anniversary hillclimb this weekend - not often you see the NZ Rally champion running his Evo against a PB Vauxhall and a Corvette Stingray on gravel! Good times.

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