Discussion
RBT0 said:
what's the disadvantage of ethanol?
The main one is that it absorbs water (even from just damp air).... thus making the fuel more corrosive The other drawback is that the vapour pressure of the fuel increases (ie bubbles form in the fuel more readily at any given temperature) - thus increasing the chances of vapour locks and hot start problems, particularly in carburettored or old tech fuel injection systems.
On the other hand we can be petrolheads and still save the planet just a tiny bit more
Edited by speedick on Tuesday 27th August 13:44
On this note, I have noticed when I fill my 600 that the fuel gun shut down the fuel after initial 1 l fill for 3-4 times before it starts again.
Is it too much vapours from the tank that is stopping the fuel?
Eventually I manage to fill the tank, but I have to wait few seconds at the beginning before the gun flow is at full capacity.
Thoughts?
Is it too much vapours from the tank that is stopping the fuel?
Eventually I manage to fill the tank, but I have to wait few seconds at the beginning before the gun flow is at full capacity.
Thoughts?
12pack said:
The higher RON only really helps to prevent situations when the sensors pick up potential knocking, and the electronics respond by retarding the timing, causing loss of power.
Mac turbo engines don’t run at very high compression ratios, so less of an issue. Probably mostly helps if you push the engine when cold, which you shouldn’t do anyway.
^^^^ This, as for any noticeable difference I'd suggest that's mainly placebo.Mac turbo engines don’t run at very high compression ratios, so less of an issue. Probably mostly helps if you push the engine when cold, which you shouldn’t do anyway.
macdeb said:
12pack said:
The higher RON only really helps to prevent situations when the sensors pick up potential knocking, and the electronics respond by retarding the timing, causing loss of power.
Mac turbo engines don’t run at very high compression ratios, so less of an issue. Probably mostly helps if you push the engine when cold, which you shouldn’t do anyway.
^^^^ This, as for any noticeable difference I'd suggest that's mainly placebo.Mac turbo engines don’t run at very high compression ratios, so less of an issue. Probably mostly helps if you push the engine when cold, which you shouldn’t do anyway.
I recall a piece written in USA where the car was running much slower on the crappy gas they had which was rectified by chucking in some high octane juice which measurably restored the performance.
I found the article it was from Motortrend, US 91 is the same as our 95RON.
I should also point out that after his first two warm-up laps, Randy complained that the engine was "pulling power" at high rpms. Even still, the McLaren 720S broke the 918 Spyder's previous record on lap two with a time of 1:23.31. Let me restate that: It beat a near million-dollar hypercar on the warm-up lap!
We looked at the GPS data traces, and sure enough on both of Big Willow's long straights, the McLaren's acceleration suddenly tapered off. The McLaren engineer on hand theorized that because the engine is meant to run 98 octane (the U.K. equivalent of our 93 octane) to prevent knock, the engine was retarding the timing, aka pulling power. Solution: We splashed in five gallons of 101 octane in an attempt to get the engine working properly. That did the trick.
Now before you start firing off the angry "McLaren cheated!" emails, please note that the Nissan GT-R also refuses to run properly on 91 octane, and for years Nissan has been supplying us GT-Rs with a case of octane booster in the trunk. If you look at a modern Porsche's owners' manual, it states that performance is reduced on 91 octane and that full performance is only available with 93. That's just how (some) cars are. I'd also like to point out that nearly ever racetrack sells race fuel on site and that $100 worth of the good stuff isn't an impediment to people who buy cars with $288,845 (base) price tags. Moreover, if Willow Springs were located in practically any other state, the Chevron would have been pumping 93 octane, not 91. Were we scientific with the fuel mixture? In other words, did the five gallons of 101 result in a perfect 93 octane rating? No. The mixture might have even been 94 or 95. Could have also been 92.5. We were in the heat of the moment and just trying to make the car run properly.
I should also point out that after his first two warm-up laps, Randy complained that the engine was "pulling power" at high rpms. Even still, the McLaren 720S broke the 918 Spyder's previous record on lap two with a time of 1:23.31. Let me restate that: It beat a near million-dollar hypercar on the warm-up lap!
We looked at the GPS data traces, and sure enough on both of Big Willow's long straights, the McLaren's acceleration suddenly tapered off. The McLaren engineer on hand theorized that because the engine is meant to run 98 octane (the U.K. equivalent of our 93 octane) to prevent knock, the engine was retarding the timing, aka pulling power. Solution: We splashed in five gallons of 101 octane in an attempt to get the engine working properly. That did the trick.
Now before you start firing off the angry "McLaren cheated!" emails, please note that the Nissan GT-R also refuses to run properly on 91 octane, and for years Nissan has been supplying us GT-Rs with a case of octane booster in the trunk. If you look at a modern Porsche's owners' manual, it states that performance is reduced on 91 octane and that full performance is only available with 93. That's just how (some) cars are. I'd also like to point out that nearly ever racetrack sells race fuel on site and that $100 worth of the good stuff isn't an impediment to people who buy cars with $288,845 (base) price tags. Moreover, if Willow Springs were located in practically any other state, the Chevron would have been pumping 93 octane, not 91. Were we scientific with the fuel mixture? In other words, did the five gallons of 101 result in a perfect 93 octane rating? No. The mixture might have even been 94 or 95. Could have also been 92.5. We were in the heat of the moment and just trying to make the car run properly.
Edited by TB993tt on Tuesday 27th August 14:30
TB993tt said:
I found the article it was from Motortrend, US 91 is the same as our 95RON.
I should also point out that after his first two warm-up laps, Randy complained that the engine was "pulling power" at high rpms. Even still, the McLaren 720S broke the 918 Spyder's previous record on lap two with a time of 1:23.31. Let me restate that: It beat a near million-dollar hypercar on the warm-up lap!
We looked at the GPS data traces, and sure enough on both of Big Willow's long straights, the McLaren's acceleration suddenly tapered off. The McLaren engineer on hand theorized that because the engine is meant to run 98 octane (the U.K. equivalent of our 93 octane) to prevent knock, the engine was retarding the timing, aka pulling power. Solution: We splashed in five gallons of 101 octane in an attempt to get the engine working properly. That did the trick.
Now before you start firing off the angry "McLaren cheated!" emails, please note that the Nissan GT-R also refuses to run properly on 91 octane, and for years Nissan has been supplying us GT-Rs with a case of octane booster in the trunk. If you look at a modern Porsche's owners' manual, it states that performance is reduced on 91 octane and that full performance is only available with 93. That's just how (some) cars are. I'd also like to point out that nearly ever racetrack sells race fuel on site and that $100 worth of the good stuff isn't an impediment to people who buy cars with $288,845 (base) price tags. Moreover, if Willow Springs were located in practically any other state, the Chevron would have been pumping 93 octane, not 91. Were we scientific with the fuel mixture? In other words, did the five gallons of 101 result in a perfect 93 octane rating? No. The mixture might have even been 94 or 95. Could have also been 92.5. We were in the heat of the moment and just trying to make the car run properly.
FWIW, sounds about in line with my post. High RON needed when pushing the car before it's completely warmed up.I should also point out that after his first two warm-up laps, Randy complained that the engine was "pulling power" at high rpms. Even still, the McLaren 720S broke the 918 Spyder's previous record on lap two with a time of 1:23.31. Let me restate that: It beat a near million-dollar hypercar on the warm-up lap!
We looked at the GPS data traces, and sure enough on both of Big Willow's long straights, the McLaren's acceleration suddenly tapered off. The McLaren engineer on hand theorized that because the engine is meant to run 98 octane (the U.K. equivalent of our 93 octane) to prevent knock, the engine was retarding the timing, aka pulling power. Solution: We splashed in five gallons of 101 octane in an attempt to get the engine working properly. That did the trick.
Now before you start firing off the angry "McLaren cheated!" emails, please note that the Nissan GT-R also refuses to run properly on 91 octane, and for years Nissan has been supplying us GT-Rs with a case of octane booster in the trunk. If you look at a modern Porsche's owners' manual, it states that performance is reduced on 91 octane and that full performance is only available with 93. That's just how (some) cars are. I'd also like to point out that nearly ever racetrack sells race fuel on site and that $100 worth of the good stuff isn't an impediment to people who buy cars with $288,845 (base) price tags. Moreover, if Willow Springs were located in practically any other state, the Chevron would have been pumping 93 octane, not 91. Were we scientific with the fuel mixture? In other words, did the five gallons of 101 result in a perfect 93 octane rating? No. The mixture might have even been 94 or 95. Could have also been 92.5. We were in the heat of the moment and just trying to make the car run properly.
Edited by TB993tt on Tuesday 27th August 14:30
But indeed personally I enjoy driving the extra mile or so to get "99" whenever I need to fill up. But its not the end of the world if you drive up to station that doesn't have it while on a road trip, e.g.
I always use shell, V Power when manufacturers recommend 98/99 octane, otherwise 95 is fine as long as its Shell. McLaren told me they always use 95 RON so I used that in my 12C on long m-way trips and 98/99 for spirited outings. My Lotus, Audi & Porsche all recommend 98+ RON so I use as recommended. 95 / 98 never made any discernible difference in my 12C I just felt better using V Power in enthusiastic driving.
There was a huge difference between 98 & 95 in my Mini Copper S and MX5 BBR turbo, both would knock on 95 and run like dogs. I never, ever use supermarket fuel, not even if its discounted to 0p per litre,
There was a huge difference between 98 & 95 in my Mini Copper S and MX5 BBR turbo, both would knock on 95 and run like dogs. I never, ever use supermarket fuel, not even if its discounted to 0p per litre,
) time ago that the only fuel retailers that had control of their own blends were Shell, Esso and Elf. RBT0 said:
Poppiecock said:
All McLarens get V-Power as their first fill at the factory - and get filled with it when they go back for servicing.
Interesting!Source?
Spend a morning or so there looking at what turns up!
Here's a Streetview shot.
LotusJas said:
But they don't go to MTC for servicing?
And first fill will be on the production line, not outside a couple of miles down the road. I don't believe new cars leave MTC under their own power.
Cars come down the road on trade plates, still covered in their protective tape and wrap and get filled up.And first fill will be on the production line, not outside a couple of miles down the road. I don't believe new cars leave MTC under their own power.
Other cars come in and they take photos of the fuel being put in, so it goes into the service history.
Poppiecock said:
RBT0 said:
Poppiecock said:
All McLarens get V-Power as their first fill at the factory - and get filled with it when they go back for servicing.
Interesting!Source?
Spend a morning or so there looking at what turns up!
Here's a Streetview shot.
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