Reading an interesting US article about how the energy levels in petrol have fallen, in US petrol over the years - this is to do with BTU/per gallon rather than octane values. He reckons that the overall your petrol has less energy in it than it used to - falling from 125,071 BTU/gallon to 121,167 BTU/gallon. He reckons that you will have to use more petrol to cover the same distance, because the fuel has less energy than it once did. Although he concedes that vehicles are more fuel efficient now, so you might not notice. He reckons that the real big difference is the use of ethanol in the fuel mix - ethanol only having energy of 76,000 BTU/gallon. So the more of that that goes in your fuel tank - the less energy you are actually getting and the more gallons/litres you will have to buy. Interesting, but not sure how it affects us compared to the US. But we are probably the same ?
From what I gather from the USA forum, is that USA has more ethanol than us, but they do have restrictions. The figures you present show very little difference as a percentage loss. Members know my maths are not good, but it appears to be less than 1%. As you say, we probably wouldn't notice in high performance motors, and the reduction might have been introduced over a period of time rather than overnight. I use only premium 'ethanol-free' fuels, and have said before that on switching I noticed I'd get an extra 10 miles per tank before the fuel light flashed. My conclusion there is that there may well be some truth in the research you've presented. Cheers! (Put premium in you R1)
I am glad someone is keeping an eye on these things - otherwise we just might not notice how we are being robbed ! When I am away I always get 98 or 100 as it does not have the ethanol mix. It is just better ! Here we do not have road tax, the tax is on the fuel so Super costs about £1.85 per litre - certainly over £1.85 compared to about £1.45 for regular 95. Anyway the the difference is closer to 3.2%. There is an easy way to calculate this on a calculator...... To find what is 121,167 as a percentage of 125,071, just do this very easy : smaller number 121,167 divide by large number 125,071 press % so 121,167 is 96.8785..% of 125,071. Difference is therefore 3.2% rounded. I use that little calc quite a lot
You obviously over rate my intelligence. I am yet to accomplish simple measurements from a tape to install tank pads, let alone enter the world of high-tech calculators. I thought I'd be able to bluff everyone by using clear tank pads, but still the found my errors. I am fine with 10% or multiples thereof though.
