Andy T 0 Posted January 18, 2007 Dont forget tesco 99RON, its cheaper than the shell stuff and from what I understand better too. I don't know where Tesco source it from but I very much doubt its better than V-Power! V-Power has some clever additives unrelated to RON that improve throttle response & power at certain RPM's, It may well be 99 RON too, and don't forget its very very similar to what they put in F1 cars! I doubt Tesco99 has the combustion chamber cleaning performance either. Talc, all modern cars have knock sensor control (as far as I know) it will just be the timing advance limit that differs. Dr_Mat, Do you think then that the Vr6/G60 limit will be set around the 98RON mark, or higher? Quote Share this post Link to post Share on other sites
StuartFZR400 0 Posted January 18, 2007 Everything else gets their best out of 98 octane and anything else is pointless. Thats how I saw it too; and even if there were any gain, you're talking a minimal percentage - better off shedding some weight or somthing, lol. We've got a bike tuned where it can only use the 98+, but again we see no point in using 100+; You can often buy this if required; a friend of ours races a 205 and has to make a specail purchse and he's all set up for the gain. Not sure what point you'd get knock; no idea if the C has continuous variable timing (like a BM of whatever) to allow for this? Presume a fair few performace cars do. Quote Share this post Link to post Share on other sites
dr_mat 0 Posted January 18, 2007 Basically it works like this.. when you start the car up, it sets the engine to 100% ignition advance. It almost always detects knock as a result of this, so it backs off the advance a few degrees at a time till it goes away. Then it advances again a degree at a time till you get knock. Then it retards again .. And it stays in this loop at all times. So if your fuel is good enough to have zero knock at 100% advance (i.e. it's running to-specification at 98 octane), then the ECU does not ever retard. Cheaper/poorer fuel results in extra retard (the VR can do up to 11 degrees of retard and controls it per-cylinder, iirc), but better fuel can't make it advance any further than 100%. All engines work like this. Therefore the only way you will get benefit from 100+ Octane is if your engine's idea of 100% advance requires 100+ Octane. Most don't, they're tuned to run their best on 98. A lot of small engines are tuned to run their best on 95, so those don't even benefit from 98, let alone 100+.. Quote Share this post Link to post Share on other sites
Garry 0 Posted January 20, 2007 I tried the BP 102 in my G60, and it did seem to make a difference. It was quite a noticable difference if the truth be told. However, the price is just too high. Quote Share this post Link to post Share on other sites
dr_mat 0 Posted January 21, 2007 Noticeable difference compared to what? Given that your car is probably 10-15 bhp more powerful when it's cold than when it's hot, can you really tell the difference if you get another 5bhp due to changing fuel? Quote Share this post Link to post Share on other sites
chubbybrown 0 Posted January 21, 2007 Bp's ultimate is batched seperately its not just a gallon of additive chucked in when the tankers on the bay at the terminal. Unsure about V power as I dont work for shell,I tend to use the shell stuff as its pretty good comapred to 95ron. The old car doesnt pink with 95a surprisingly as I thought according to the book it should run on 98 anyway. So for me Im only running it on what its supposed to be run on. My mitsi should be run on super+ too :nuts: Quote Share this post Link to post Share on other sites
jonnyboyo 0 Posted February 3, 2007 A recent test in Banzai (when i had my GT4) did a controlled petrol test on Shell Optimax 98 RON (before it changed to V-Power 99), BP Ultimate, tesco 99 RON and standard unleaded. Although Tesco's 99 had the highest RON number, it was with running the Optimax that they could advance the timing more before knocking occured. The most expensive of the fuels tested but was the best. The tests were conducted fairly by draining and flushing the tanks before every fuel swap. In fairness to Tesco's 99, it was highly praised too and if my memory serves me correctly it performed at least as good as BP Ultimate if not better, and MUCH cheaper. Quote Share this post Link to post Share on other sites
TheWizardofOdds 0 Posted February 4, 2007 A recent test in Banzai (when i had my GT4) did a controlled petrol test on Shell Optimax 98 RON (before it changed to V-Power 99), BP Ultimate, tesco 99 RON and standard unleaded. I love Banzai.. It's all a con,no doubt-we're so gullable(sp?).I buy BP Ultimate religiously-can I tell the diff?-No. Do I get more wotsits per thingys?-probably not.It's like buying free-range eggs or whatever;you know you're being conned but paying extra as you are,it makes you feel ok about it. Quote Share this post Link to post Share on other sites
PhatVR6 0 Posted February 4, 2007 All down South. What's up..............Northern money not good enough :lol: No, we get blessed with all that cold, dense air instead. Quote Share this post Link to post Share on other sites
alex303 0 Posted February 4, 2007 I always used to use Optimax (or whatever it's called now) but to be fair got caught short the other day and filled up on the Sainsbury's 98 Ron Super and to be fair the old girl seemed to love it (not bad for 0.86p per litre too)! Quote Share this post Link to post Share on other sites
Garry 0 Posted February 4, 2007 Noticeable difference compared to what? Given that your car is probably 10-15 bhp more powerful when it's cold than when it's hot, can you really tell the difference if you get another 5bhp due to changing fuel? Compared to my push bike Joking a side, it felt a bit more torquey. I know (and agree) with what your saying about the cold/damp thing dr_matt, but I also know my cars day-to-day running characteristics a little better than you. Quote Share this post Link to post Share on other sites
dr_mat 0 Posted February 5, 2007 I'm sure you do know your car's running characteristics better than me (it would be a little weird if it were otherwise!).. Just saying the only times I've felt a difference due to filling up with new fuel it's been because the car is now 65 kg heavier ... ;) Ok the VR isn't forced induction, so maybe it makes more difference, but I didn't think the G60 ECU was smart enough to make the best of changes like that. Quote Share this post Link to post Share on other sites
Garry 0 Posted February 5, 2007 I will try to explain... The difference seemed to be with the low down torque. The car needed very little throttle movement (Less than normal) at low speed/RPM to accelerate/pull. Below 50mph in normal urban driving ie stop/start it seemed very crisp if that makes sense. As for the balls out grunt, I have absolutely no idea if it made any difference at all. I didn't get a chance to open the flood-gates due to traffic conditions. Maybe this is where the ECU overrides it all? I don't know enough about the G60 ECU to comment really, all I can say is it felt different. However, it would make an interesting experiment to conduct on a rolling road. The same car with the same enviromental conditions. This way you could analize the whole torque/power spectrum, and see what is really happening. Quote Share this post Link to post Share on other sites
Andy T 0 Posted February 6, 2007 I've noticed improvements in both the G60 and the VR6 when using V-Power, probably slightly more so in the VR6, especially at part throttle. Both cars specify 98 ron on the filler flap so using anything lower will reduce performance. Quote Share this post Link to post Share on other sites