Posh Petrol - worth it?
Discussion
Since getting my Elise, I have been filling her up on Shell 99 RON stuff in the belief that it's the best on the market - cleaner and will get better performance. And it's more expensive, which everyone knows means it must be better.
I remember reading a review in EVO mag (I think) that reckoned highly tuned turbo cars see big improvements in performance with high octane fuel, but otherwise, there's not much point. I remember in my old WRX Scooby that putting higher octane fuel in made it noticably perkier, but I wonder whether this is a feature of the turbo engine or a clever ECU.
Anyway, my question is whether there is any real benefit in a N/A Elise? Does the ECU recognise the different combustion characteristics and adjust accordingly, or is it just throwing money away. Now that I see fuel costs creeping up again (BP Ultimate in my Golf last night at 110.9!), the question seems more relevant.
Sorry if this has been done to death already!
B
I remember reading a review in EVO mag (I think) that reckoned highly tuned turbo cars see big improvements in performance with high octane fuel, but otherwise, there's not much point. I remember in my old WRX Scooby that putting higher octane fuel in made it noticably perkier, but I wonder whether this is a feature of the turbo engine or a clever ECU.
Anyway, my question is whether there is any real benefit in a N/A Elise? Does the ECU recognise the different combustion characteristics and adjust accordingly, or is it just throwing money away. Now that I see fuel costs creeping up again (BP Ultimate in my Golf last night at 110.9!), the question seems more relevant.
Sorry if this has been done to death already!
B
It is an advertising led misconception. There are only 4-5 refineries in the UK, for the south ALL fuel comes from Esso Fawley. A few distributers will put the odd specific additive in the fuel to help keep the engine clean but as a general rule the basic fuel delivered by all pumps is the same. It annoys the hell out of me when that stupid e-mail comes round that says we should boycott esso. How?, If I go to the local Shell, I am still buying from Esso Fawley, the only thing I am doing is harming he bloke who has purchased a franchise.
This is a whole complex issue but the basics fact that weather you have 95 RON or 101RON fuel, the calorific value of the fuel is the same. The only difference is that the high RON fuel has an additive that makes it easier to vaporise. The fuel mist ejected by the injector is finer, the fuel therefore has a larger surface area and burns quicker. Good quality, clean fuel injectors will give the same advantages (to an extent).
This is a whole complex issue but the basics fact that weather you have 95 RON or 101RON fuel, the calorific value of the fuel is the same. The only difference is that the high RON fuel has an additive that makes it easier to vaporise. The fuel mist ejected by the injector is finer, the fuel therefore has a larger surface area and burns quicker. Good quality, clean fuel injectors will give the same advantages (to an extent).
Gooby said:
It is an advertising led misconception.
This is a whole complex issue but the basics fact that weather you have 95 RON or 101RON fuel, the calorific value of the fuel is the same. The only difference is that the high RON fuel has an additive that makes it easier to vaporise. The fuel mist ejected by the injector is finer, the fuel therefore has a larger surface area and burns quicker. Good quality, clean fuel injectors will give the same advantages (to an extent).
Take your point about the refineries, but surely the ads about cleaner engine internals cannot be fake? (Trading/advertising standards and all that)This is a whole complex issue but the basics fact that weather you have 95 RON or 101RON fuel, the calorific value of the fuel is the same. The only difference is that the high RON fuel has an additive that makes it easier to vaporise. The fuel mist ejected by the injector is finer, the fuel therefore has a larger surface area and burns quicker. Good quality, clean fuel injectors will give the same advantages (to an extent).
Not scientific I know, but I am sure I get 4-5 more mpg on high octane - although yes, performance seems much the same - so the extra cost is wiped out, and if - as I hope - the engine is running cleaner,then I see it as a good deal.
Admit I am not entirely convinced, but as it works out the same price, I may as well stick with it.
I find that my K-series feels slightly less lethargic when cold if it's got higher octane fuel in it but otherwise it makes no noticeable difference. I certainly can't tell Optimax from other high-octane fuels.
I generally use Asda 95RON fuel because it happens to be the nearest petrol station.
I generally use Asda 95RON fuel because it happens to be the nearest petrol station.
Edited by kambites on Wednesday 13th May 10:25
jondude said:
Gooby said:
It is an advertising led misconception.
This is a whole complex issue but the basics fact that weather you have 95 RON or 101RON fuel, the calorific value of the fuel is the same. The only difference is that the high RON fuel has an additive that makes it easier to vaporise. The fuel mist ejected by the injector is finer, the fuel therefore has a larger surface area and burns quicker. Good quality, clean fuel injectors will give the same advantages (to an extent).
Take your point about the refineries, but surely the ads about cleaner engine internals cannot be fake? (Trading/advertising standards and all that)This is a whole complex issue but the basics fact that weather you have 95 RON or 101RON fuel, the calorific value of the fuel is the same. The only difference is that the high RON fuel has an additive that makes it easier to vaporise. The fuel mist ejected by the injector is finer, the fuel therefore has a larger surface area and burns quicker. Good quality, clean fuel injectors will give the same advantages (to an extent).
Not scientific I know, but I am sure I get 4-5 more mpg on high octane - although yes, performance seems much the same - so the extra cost is wiped out, and if - as I hope - the engine is running cleaner,then I see it as a good deal.
Admit I am not entirely convinced, but as it works out the same price, I may as well stick with it.
I do a hell of a lot of miles (86k in 4 years) and I dont notice a difference but on a track day I stick in high octane for a few fill before and after.
Supermarket fuels are of a decent quality and even better since they were in trouble a while back.
put anything you like in it, unless:
you have a forced induction car or an NA car thats mapped specifically for it/has an adaptive ECU that will take advantage of it
on my old RS6, it was remapped to give its best on 97 or higher, as was my old SC Honda Elise
but in a regular - waste of money
even all this "cleaning additive" bull is just marketing to get you to go to a brand of garage - how many people even keep their cars long enough, to get the benefit of say 120K or 150K miles out of an engine? ...in the meanwhile every tank you put in is a £5 more LOL
they are laughing all the way to the bank
you have a forced induction car or an NA car thats mapped specifically for it/has an adaptive ECU that will take advantage of it
on my old RS6, it was remapped to give its best on 97 or higher, as was my old SC Honda Elise
but in a regular - waste of money
even all this "cleaning additive" bull is just marketing to get you to go to a brand of garage - how many people even keep their cars long enough, to get the benefit of say 120K or 150K miles out of an engine? ...in the meanwhile every tank you put in is a £5 more LOL
they are laughing all the way to the bank
Forced induction may be the key point then. As I say, I definitely saw performance improvements in my old WRX, and my current Golf (2.0 Turbo) sees about a 10% increase in efficiency on the commute, which means it pays for itself.
The answer is staring me in the face - I need to put a supercharger on my 111R
b
The answer is staring me in the face - I need to put a supercharger on my 111R
b
I recently started using the "super" Petrol at my local supermarket, purely because I was interested in seeing if there were any benefits.
Initially I didnt notice a thing, but by the time I had used about half a tank, there was a noticable improvement to throttle response and the car did seem to rev/breath better. The latter maybe purely psycological, but hey, it feels better so it is.
MPG wise I've seen about 25miles per tank, so given I'm adding just over 8 gallons each time I fill it up I'm seeing about a 3 MPG improvement, which is about a 8-10% improvement, which is more than the additional cost of the higher RON
Initially I didnt notice a thing, but by the time I had used about half a tank, there was a noticable improvement to throttle response and the car did seem to rev/breath better. The latter maybe purely psycological, but hey, it feels better so it is.
MPG wise I've seen about 25miles per tank, so given I'm adding just over 8 gallons each time I fill it up I'm seeing about a 3 MPG improvement, which is about a 8-10% improvement, which is more than the additional cost of the higher RON
for sure - on a per car basis, some cars do seem to give better mpg on particular fuel ...it seems to me to be more chance than anything though, that one owns a car that likes the local BP 97 (whatever) - if you find something that consistenly works you for then of course its a no brainer to stick to it
ive had a few cars where its made no difference....others where its really noticiable ....30-40bhp on a 1.8ton estate just from putting 97/98/99 in the tank is a good upgrade
...but defo a waste on a std K series engined Elise - it dosent have a sensor, to even detect what RON of fuel you are putting in !
ive had a few cars where its made no difference....others where its really noticiable ....30-40bhp on a 1.8ton estate just from putting 97/98/99 in the tank is a good upgrade
...but defo a waste on a std K series engined Elise - it dosent have a sensor, to even detect what RON of fuel you are putting in !
I've been experimenting since going to the Porker. I have noticed marginal improvements in mpg (maybe as much as 3mpg) allowing for me driving relatively consistently but not really been able to judge on performance, so nothing blatant.
FYI, I use this site http://www.petrolprices.com/ to work out where my cheapest fuel is as I have noticed I can buy Super 97 in Southampton at the same price as regular 95 at my Local Texaco in Sandbanks. When there is nothing in it I like to "treat" my car to the stronger stuff. However doing the maths .....
Cost per litre in pence
MPG 93.9 94.9 95.9 96.9 97.9 98.9 99.9
20 £0.2136 £0.2159 £0.2182 £0.2204 £0.2227 £0.2250 £0.2273
21 £0.2035 £0.2056 £0.2078 £0.2100 £0.2121 £0.2143 £0.2165
22 £0.1942 £0.1963 £0.1983 £0.2004 £0.2025 £0.2045 £0.2066
23 £0.1858 £0.1877 £0.1897 £0.1917 £0.1937 £0.1957 £0.1976
24 £0.1780 £0.1799 £0.1818 £0.1837 £0.1856 £0.1875 £0.1894
25 £0.1709 £0.1727 £0.1745 £0.1764 £0.1782 £0.1800 £0.1818
26 £0.1643 £0.1661 £0.1678 £0.1696 £0.1713 £0.1731 £0.1748
27 £0.1582 £0.1599 £0.1616 £0.1633 £0.1650 £0.1667 £0.1684
28 £0.1526 £0.1542 £0.1558 £0.1575 £0.1591 £0.1607 £0.1623
29 £0.1473 £0.1489 £0.1505 £0.1520 £0.1536 £0.1552 £0.1567
30 £0.1424 £0.1439 £0.1454 £0.1470 £0.1485 £0.1500 £0.1515
31 £0.1378 £0.1393 £0.1408 £0.1422 £0.1437 £0.1452 £0.1466
32 £0.1335 £0.1349 £0.1364 £0.1378 £0.1392 £0.1406 £0.1420
33 £0.1295 £0.1308 £0.1322 £0.1336 £0.1350 £0.1364 £0.1377
34 £0.1257 £0.1270 £0.1283 £0.1297 £0.1310 £0.1324 £0.1337
35 £0.1221 £0.1234 £0.1247 £0.1260 £0.1273 £0.1286 £0.1299
36 £0.1187 £0.1199 £0.1212 £0.1225 £0.1237 £0.1250 £0.1263
37 £0.1155 £0.1167 £0.1179 £0.1192 £0.1204 £0.1216 £0.1229
38 £0.1124 £0.1136 £0.1148 £0.1160 £0.1172 £0.1184 £0.1196
39 £0.1096 £0.1107 £0.1119 £0.1131 £0.1142 £0.1154 £0.1166
40 £0.1068 £0.1079 £0.1091 £0.1102 £0.1114 £0.1125 £0.1136
Table showing petrol cost per mile
I can see that doing 25mpg at (notional 97RON) 96.9 is cheaper per mile than doing 24mpg at (notional 95RON) 93.9. So I pretty much know for my porker that if perception that 97RON can be more efficient and I can get just 1 mpg extra for less than a 3p per litre premium, super is more cost effective to me... but as cost per mile reduces (i.e. more economical cars) it's the law of diminishing returns, so a 3p premium at 35mpg for an extra 1mpg does not pay, 2mpg then yes, or 1mpg at only a 2p uplift too.
But as you can see we are talking fractions of pence and ultimately it's down to that right foot.
Sorry for the formatting.
FYI, I use this site http://www.petrolprices.com/ to work out where my cheapest fuel is as I have noticed I can buy Super 97 in Southampton at the same price as regular 95 at my Local Texaco in Sandbanks. When there is nothing in it I like to "treat" my car to the stronger stuff. However doing the maths .....
Cost per litre in pence
MPG 93.9 94.9 95.9 96.9 97.9 98.9 99.9
20 £0.2136 £0.2159 £0.2182 £0.2204 £0.2227 £0.2250 £0.2273
21 £0.2035 £0.2056 £0.2078 £0.2100 £0.2121 £0.2143 £0.2165
22 £0.1942 £0.1963 £0.1983 £0.2004 £0.2025 £0.2045 £0.2066
23 £0.1858 £0.1877 £0.1897 £0.1917 £0.1937 £0.1957 £0.1976
24 £0.1780 £0.1799 £0.1818 £0.1837 £0.1856 £0.1875 £0.1894
25 £0.1709 £0.1727 £0.1745 £0.1764 £0.1782 £0.1800 £0.1818
26 £0.1643 £0.1661 £0.1678 £0.1696 £0.1713 £0.1731 £0.1748
27 £0.1582 £0.1599 £0.1616 £0.1633 £0.1650 £0.1667 £0.1684
28 £0.1526 £0.1542 £0.1558 £0.1575 £0.1591 £0.1607 £0.1623
29 £0.1473 £0.1489 £0.1505 £0.1520 £0.1536 £0.1552 £0.1567
30 £0.1424 £0.1439 £0.1454 £0.1470 £0.1485 £0.1500 £0.1515
31 £0.1378 £0.1393 £0.1408 £0.1422 £0.1437 £0.1452 £0.1466
32 £0.1335 £0.1349 £0.1364 £0.1378 £0.1392 £0.1406 £0.1420
33 £0.1295 £0.1308 £0.1322 £0.1336 £0.1350 £0.1364 £0.1377
34 £0.1257 £0.1270 £0.1283 £0.1297 £0.1310 £0.1324 £0.1337
35 £0.1221 £0.1234 £0.1247 £0.1260 £0.1273 £0.1286 £0.1299
36 £0.1187 £0.1199 £0.1212 £0.1225 £0.1237 £0.1250 £0.1263
37 £0.1155 £0.1167 £0.1179 £0.1192 £0.1204 £0.1216 £0.1229
38 £0.1124 £0.1136 £0.1148 £0.1160 £0.1172 £0.1184 £0.1196
39 £0.1096 £0.1107 £0.1119 £0.1131 £0.1142 £0.1154 £0.1166
40 £0.1068 £0.1079 £0.1091 £0.1102 £0.1114 £0.1125 £0.1136
Table showing petrol cost per mile
I can see that doing 25mpg at (notional 97RON) 96.9 is cheaper per mile than doing 24mpg at (notional 95RON) 93.9. So I pretty much know for my porker that if perception that 97RON can be more efficient and I can get just 1 mpg extra for less than a 3p per litre premium, super is more cost effective to me... but as cost per mile reduces (i.e. more economical cars) it's the law of diminishing returns, so a 3p premium at 35mpg for an extra 1mpg does not pay, 2mpg then yes, or 1mpg at only a 2p uplift too.
But as you can see we are talking fractions of pence and ultimately it's down to that right foot.
Sorry for the formatting.
Edited by Grinnders on Wednesday 13th May 14:09
I fill up with Tesco 99 every so often, it certainly returns a slightly better MPG but there are no real performance gains with a K series S2. The Impreza is very different however, it has a sticker on the fuel cap telling you to put no lower than 98RON in it, on the odd occassion I've had to put poor peoples fuel in it it's run like a dog and pinks really badly. The Lotus isn't so high strung.....
In the 4 Elises I've had (each of which with engines in various states of tune), I've found the single most successful method of extracting better performance has been to work on my driving skills to enable me to keep my right foot pinned against the bulkhead on the throttle pedal for as much time as possible whilst heading in a northerly direction.
Spend good money on oil, tyres and pads, worry only about fuel if your engine is specifically mapped to take advantage of it.
Spend good money on oil, tyres and pads, worry only about fuel if your engine is specifically mapped to take advantage of it.
Gassing Station | Elise/Exige/Europa/340R | Top of Page | What's New | My Stuff