OT: Engine tuning from the nozzel

[webby]

Who remermers the old ESSO advert "Put a tiger in your tank"?

Well, Shell Germany have started selling 100 octane petrol.

As competition among the various petrol stations increases, Shell have launched a major advertising campaign (featuring crashing petrol coloured waves and a black rearing stallion that looks suspiciouly similar to Ferarris) for the newly released "Champagne of Petrol" - 100 Octane special brew.

They claim a 10% increase in perfrormance across a broad range of all vehicle types.

There has been some hefty discussion in the German papers and on TV about this for 2 main reasons.

1. If the new petrol (which by the way sell for €1.19 a litre as opposed to €1.04 for 98 "Super") doesnt give your car a 10% performance increase then Shell have been telling porkies and have an advertising compliants problem.

2. If the new stuff does give a 10% increase it may invalidate your insurance which is tied directly the vehicle manufacturers specifications.

Last evening Shell spokespersons were very careful with thier choice of words when describing the new fuel. "10% faster acceleration", etc. etc...

In dyno tests shown on German TV last evening one of the test cars a 1.8 litre combi managed a 3.4% increase in output whereas the second car, a Ford 1.8 something or other managed only 0.9%.

Anyone in Germany (Markc) tried it yet?

[rob_wijhenke]

I haven't tried it but when I switched from 95RON to 98RON I noticed a 12% increase in top speed, acceleration and millage so I guess switching from 98 to 100 definitely is worth it! Can't wait to show off my new petrol to all my friends on my next trackday.

[MarkC]

I haven't tried it either, as I'm able to buy ESSO's (and BP on the Autobahn) Super-Plus (98RON?) fuel at about €.43 per liter via rationed pre-paid fuel coupons (in Germany only). With this, it's hard to Justify paying €1.19 per liter of 100RON. However, when I make another Alps trip and need fuel in a country other than Germany, or if I find my tank running low with no ESSO nearby, I just may give it a try.
MarkC

[rob_wijhenke]

Marc, you're missing the point here, free HP for only a few cents per liter! What else do you want? I'm already surfing&searching the web for RON 102! I also heard about this secret additive that will give you a 20% boost!

[Robert Au]

Originally posted by webby
They claim a 10% increase in perfrormance across a broad range of all vehicle types.

Optimistic in the extreme.

I'd be interested to know if they're claiming a reduction in engine deposits over RON 98 as the detergent additives in RON 98 (at least here in Australia) are pretty impressive in terms of internal build-up.

Also, is it perfumed ??. This has been canvassed (I'm not joking), but none of the Companies are owning up at the moment.

Kind regards,

Robert

[1967 R50/2]

I suspect that the secret behind Shell's claims is in the fine print: How do you define performance? Rear Wheel HP? Engine longevity? Reliability? Exhaust emission reduction? Fuel efficiency? Some combination of the above?

I suspect that this stuff will burn cleaner than R0N 98...thus a 10% improvement in emission reduction. Just a hunch.

[MarkC]

Hey Rob, I'm still saving for those high-flow fuel clamps you told me about (still can't find them ), so I cannot afford that Shell 100ron.

€1.19 per liter, that's about $1.40US (at today’s exchange rate) and 1 US gallon is 3.785 liters: 3.785 X $1.40 = $5.30 a US gallon

MarkC

[webby]

Check out the v-power website (in German!).

According to Micheal Schumacher (who helped with the testing) "Its the best petrol I've ever driven". If that doesnt justify the price I dont know what will....

This page (again in German) goes to great lengths to say that the new fuel is the only guarenteed 100 octane petrol generally available in Germany and has a very special "Friction reducer".

[roger albert]

Here's the real point that it would seem everyone is missing.

In any event, it's a ridiculous claim and utterly w/o technical merit.
It's not going to by you ANY horsepower on a motor that isn't currently pinging. Octane does NOT add power (in fact, the higher octance fuels have a specific energy that is approaching 0.5% LESS.

The ONLY way it can add any power is on a motor with knock control (many many modern car motors, but as far as I know, only on HDs in the motorcycle world) On such a motor, the basic ignition timing and compression are pretty aggresive. The ECU looks for any sign of knock and retards as appropriate/required. Just dumping higher octane gas in will not buy you a single horsepower. You're far more likely to lose 1/4 horse.

MARKETING

roger

p.s.
you could advance your timing a bit, or bump up your compression ratio, or have a chip custom mapped. Those would all help when used with this gas, but by itself...nothing

[rob_wijhenke]

Here's some scientific proof of gaining HP with higher octane fuel:

"
Increase the compression ratio - Higher compression ratios produce more power, up to a point. The more you compress the air/fuel mixture, however, the more likely it is to spontaneously burst into flame (prior to the spark plug igniting it). Higher octane gasolines prevent this sort of early combustion. That is why high-performance bikes generally need high octane gasoline - their engines are using higher compression ratios to get more power. Higher octane fuel increases compression. The table below can be used as a rough guideline:
RON 93 - baseline
RON 95 - 6% increase against baseline
RON 98 - 8% increase against baseline
RON 100 - 12 to 14% increase against baseline
RON 100+ will require technical modifications that will not outweigh the advantages of using this special fuel.
"

[roger albert]

Sure, that's the most basic of tuning design rules, but, also proof of my point, as originally stated: That putting in higher octane gas in a motor with out modifications to compression ratio (and/or ignition timing) will do absolutely nothing positive.

The only way to tune with the nozzle is to only fill your tank half way.
Mass savings are always nice.

This special gas will do nothing for a regular S.

The table only illustrates the octane increases necessary for the compression ratio increases which would be necessary to extract that extra power. Octane does not (all other things being equal) mean horsepower. Never did and never will. Phyics and chemistry are picky about being violated

roger

[1967 R50/2]

Just cut the crap and go with a turbo diesel. Super hi octane. Super hi compression. Monster torque. Compact package.

Once the new diesel regs go into effect in the US in 2005 we should start to see euro turbo diesels imported. Right now though, not one would pass emission standards with the current fuel unless they were detuned.

[rob_wijhenke]

Well, I don't care what you think, I'm gonna buy me a few barrels of that 100 stuff. Can't wait for the extra gain on top the gain on the gain since I already use RON 98 Shell high quality fuel only!

[Dave Hopkins]

Rob & Roger, I think you guys are arguing and re-enforcing what the other said at the same time? The purpose of higher octane is a slower burn rate to help tolerate pre-ignition. If you have advanced the timing, raised the compression (pumping pressure) by either the compression ratio or advancing the cam for an earlier point of closing the intake to start the compression stroke, then a higher octane may be of use, on a stocker it is meaningless.

[roger albert]

Could be Dave,

My only point is that dumping higher octane gas in the same old (properly tuned / set-up) conventional motor with out the smarts
to dynamically configure either ignition (or in the case of forced
aspiration -- boost pressure) will not yield additional power.

I might as well expect increased spring preload to change my spring rate.

[Robert Au]

Originally posted by roger albert
This special gas will do nothing for a regular S.

Not Quite. It will keep the internals cleaner, but that's a consequence of the detergent additives that can be economically added for the price premium the Oil companies receive.

Again, I'd like the RON100 engine deposit claims and/or test results.

Further, the Oil company internal testing that I've seen suggests that adjusting for all other factors a motor will run slightly cooler on RON98 as opposed to RON91.

Roger?

Kind regards,

Robert

[sakurama]

You know Roger is absolutely correct. You only put in the octane that your engine needs. Unless the fuel is oxygenated it won't do anything to a stock S. I experimented with different gas in my race bikes - from 110 to 118 and it made no difference since my engine was optimized for 110. Like Roger says, if you build the engine to the point it pings than by all means raise the octane but it's a joke to put in anything higher than will keep your engine from pinging. Unless you get to put a cool sticker on your fairing...

Gregor

[rob_wijhenke]

100 is a cool number. I want 100 in my fuel. R(1)100S also has 100 in it. In fact 10*100+100. So 100 must be good! I was thinking to achieve 100 with 98 fuel by adding 2% extra fuel in the gas-tank each time. This formula y=int(x-(x/1.02)+x) supports this so you can get your extra horsies by just 'filling her up'

[roger albert]

hmmmmm, I'd forgotten the int function.
I withdraw all rebuttal now

[roger albert]

Oh yeah, and the engine could run (insignificantly) cooler, because the higher octane fuel has more additives (detergents and knock inhibitors) and _less_ actual fuel.
It will make (insignificantly) less power, and heat. You could get the same effect by rolling the throttle forward 2 degrees.