Super Unleaded....!???

[JohnnyDangerous]

Tesco Momentum for the win !!!!!!!

 

[Red993C4]

As a day job, I regularly test fuels back to back for power, torque and brake specific fuel consumption (a measure of a fuels specific power output vs weight. We measure in Lbs/hp/hour with our engine dyno, after entering the measured specific gravity of the fuel).

I'm just surprised that you still measure or express BSFC in imperial units in 2013?

One more finding, on VPower Nitro, my OIL consumption rose! Food for thought....

Any theories as to why this fuel might increase oil consumption? :?:

 

[DynoMike]

As a day job, I regularly test fuels back to back for power, torque and brake specific fuel consumption (a measure of a fuels specific power output vs weight. We measure in Lbs/hp/hour with our engine dyno, after entering the measured specific gravity of the fuel).

I'm just surprised that you still measure or express BSFC in imperial units in 2013?

One more finding, on VPower Nitro, my OIL consumption rose! Food for thought....

Any theories as to why this fuel might increase oil consumption? :?:

We run an American dyno, hence the Stone-age measurements! The best BSFC numbers we have seen have been 0.35. Our BSAC figures are expressed the same way too. Here, the high revving bike motors are less efficient, often 5 lbs/hp/hr, rising above 6 at very high rpm. VE values are typically 110% plus. Lower revving car engines regularly run BSACs in the 4s, with VE down around 102-104%.

The main reason we stick with these Olde-Worlde standards, is that I have an archive stretching back to 1986, so I'm reluctant to change! Old Dogs, New Tricks.... We can calibrate to g/kwhr but I would be on the calculator all the time so chose to leave it alone

The oil consumption? Not really sure. I think I read somewhere that the Nitro carries an upper cylinder lubricant, which may be making the oil control/second ring combination less effective. Driving conditions were the same for both fuels. I will research some more, any excuse to drive these wonderful cars :thumb:

 

[NS80]

Tesco's Momentum 99 is my fuel of choice when in Britain, and when in Australia, I used Caltex's Vortex 98.
I have found that Caltex's special provides much better range than does Momentum 99, but with only minimally less potency (the latter being in keeping with Caltex's Vortex having a lower R.O.N.).
(Before somebody says something, yes, the test subjects are the same).

The reason why Shell's top-of-the-range is well known and 'believed' is due to the advertising and marketing.

 

[nhenson]

Tesco's Momentum 99 is my fuel of choice when in Britain, and when in Australia, I used Caltex's Vortex 98.

Where do you fill up in between?.... :?

 

[2hot2trot]

I'm frankly quite surprised by what I've read above, because although I usually fill my 997.1 C4 with super unleaded, the last time I filled it with regular unleaded more than once in a row (as the pump for super wasn't working on each occasion) it honestly made no appreciable difference to my C4's fuel economy figures whatsoever - as I definitely paid regular attention - being mindful that I'd changed over, yet still saw the usual numbers for each full tank of regular - which I should also add didn't change at all, after I returned to super.

My curiosity has now been roused - so when people are suggesting that they're getting better mpg for super as opposed to regular, what real world difference is it making to your mpg figure, in your pride & joy?

 

[rossman999]

My curiosity has now been roused - so when people are suggesting that they're getting better mpg for super as opposed to regular, what real world difference is it making to your mpg figure, in your pride & joy?

TBH i don't see a lot of difference in fuel consumption, driving like miss daisy I may get 27, driving normally I am normally within the 22 -24 range on either the cheep or good stuff.

The good stuff, does make a significant difference in the bike though, adding an additional 10 miles on a 80 mile tank range, but more importantly it runs so much better.

I suspect the electronics in the Porsche are so much better and it is able to adapt quickly to the poverty spec

 

[davidjf7]

Tesco Momentum or Shell V Power for me

Usually Tesco because it's more convenient on my commute, but I do worry slightly about the possible lack of cleaning agents etc :?:

Was in Montreal last week where their 'super' is 91 Octane

 

[JohnnyDangerous]

Tesco Momentum or Shell V Power for me

Usually Tesco because it's more convenient on my commute, but I do worry slightly about the possible lack of cleaning agents etc :?:

Was in Montreal last week where their 'super' is 91 Octane

The US and prob Canadian ratings are diff, its all to do with MON and RON and will take somebody cleverer than me to explain (I have a low IQ apparently as i park in disabled spaces because I cant walk very well)

 

[Touji]

US/CAN (And more probably) use MON+RON/2 to give an average of the values, apparently (and I'm probably wrong, but doing this from memory) this is to remove the or average out the variations in altitude and temperature influencing the combustion rating of the fuel?

 

[JohnnyDangerous]

US/CAN (And more probably) use MON+RON/2 to give an average of the values, apparently (and I'm probably wrong, but doing this from memory) this is to remove the or average out the variations in altitude and temperature influencing the combustion rating of the fuel?

^ Told you !!!! :dont know:

 

[davidjf7]

US/CAN (And more probably) use MON+RON/2 to give an average of the values, apparently (and I'm probably wrong, but doing this from memory) this is to remove the or average out the variations in altitude and temperature influencing the combustion rating of the fuel?

^ Told you !!!! :dont know:

Learn something new every day :thumb:

Bit of googling suggests there's not much difference between US/Can fuel and ours

 

[Red993C4]

US/CAN (And more probably) use MON+RON/2 to give an average of the values, apparently (and I'm probably wrong, but doing this from memory) this is to remove the or average out the variations in altitude and temperature influencing the combustion rating of the fuel?

^ Told you !!!! :dont know:

Learn something new every day :thumb:

Bit of googling suggests there's not much difference between US/Can fuel and ours

Assuming that this Wikipedia article is accurate and up to date, that would appear to be true:

http://en.wikipedia.org/wiki/Octane_rating

The important data is shown in the extract below.

Porsche engines for the European market are mapped to run optimally with 98RON / 88MON German Super Plus fuel, whereas the best grade listed for North America ("Premium" or Super Unleaded") is 97RON / 87-88MON. However, I believe a problem arises in the USA due to this grade not being universally available.

 

[JohnnyDangerous]

Just spent saturday at Santa Pod and I tried some octane booster in the fuel, before using the car was running consistent terminal speeds of 117/118mph after the octane booster put in and ecu reset the speeds went up consistently
to 120 mph and this was with a noticeably stronger headwind, the octane rating after using the booster would have been around 105, car feels a little more urgent as well and thats coming from SWMBO who does not understand this !!!!

 

[RJKflyer]

Just spent saturday at Santa Pod and I tried some octane booster in the fuel, before using the car was running consistent terminal speeds of 117/118mph after the octane booster put in and ecu reset the speeds went up consistently
to 120 mph and this was with a noticeably stronger headwind, the octane rating after using the booster would have been around 105, car feels a little more urgent as well and thats coming from SWMBO who does not understand this !!!!

You mean Tesco PLUS octane booster?

Not sure how that can actually work unless the octave booster is also raising the energy density? (Sorry if i have missed the very answer as i skimmed the thread).