what petrol type

Always go with the higher octane with any sort of BMW

actually the best gas to use is the lowest octane the burns properly (gives max power and efficiency). im guessing 91 octane would be more than good for the car. the higher the octane not needed is just a waste of money and absolutely no performance gains

really? i find in my 318ti that the higher octane fuel helps minimize the time from when i hit the accelerator to when the engine kicks in

If you don"t know what you are saying don"t speak! The higher octane value get you more power! The problem is not in octans but in lead (Pb) the better fuels has a smaller amount of Pb so they are not so sutablle for older engines and can cause valve damidge and reduce engines life time! My recomandation is that you use higher octane because is more funn to drive with more power! You forgot to say what year is your Bmw I have E30 M3 323is

Why are you talking then???? Cause you obviously don't know what you're saying. Higher octane fuel is less flammable than lower octane fuel. Which means it's able to be compressed down further before detonation in the cylinder. Which means if your timing is set up for a fuel of 91 octane then you lose power and waste money by using anything higher! Higher octane above what's rated does NOT give more power.

Lets go slow for You! Higher octane value gives you more controled fiering because of its higher octane number its more harder to get fired! So your fuel is fired just by the spark and you dont have unvonted detonations caused by self fiering(hi temperature in the cilindars ....). If the engine has a knock sensor and this one has it in higher rpm with a fuel which has smaller octane value can happend detonatios! When detonations occure knock sensor senses them sends the information into ECU which reduces your intertake mistcure (air gas) and you lose some power! This is very small so if you dont look very much on gas money use higher octane fuel! Just for Your informatio Bad fuels can and will short your engines life time! And if you think that i dont know anythig about this i have made: Suzuki Swift Gti Bimoto Turbo 568hp and it is a 10s car Suzuki Swift Gti 4x4 Turbo Compresor 300hp Lotus elise 2xSuzuki Gsx-r 1000 turbo kit 520hp wtih pingel poer shift street race time 9.8s Golf 2 1.8T 392hp Golf 1 bimoto 2x1.8T 700hp Bmw E30 M3 I would like to see your cars but i think that You are just good wit words not with hands!

318is had the same engine 1990-91 in E30 and with small part modification in E36 1991-98 In Europe in which is made there is no 89 octane benzine from the end of 80"s There was Regular 91 and Super 95, 98 in the yers that this car was made!!! In 1995 there first introduced Euro super 95BS which has small percent of leader! Soo all Your Stupid Things that You sad About this car are Idiotic as You they can be taken in considewration for American Muscule car but not for European S-4 block and 16V head Opel Callibra which has been made in the same year than the Bmw had a connector and You could change Gas 91 ore 95 soo it was made for bouth fuels!

Just filled my 2009 BMW 320i with 91 instead of the regular 95. Just by mistake... Will that affect my car's engine?

Although people say that higher octane gives you better performance. Ive used 95 octane for 1 year in my 2007 320i. It always felt slow and sluggish when changing gears. And it would always rev higher before shifting gears like the timing was out or something. So ive started using 91 octane, and OMG it drives really smooth, really responsive and shifts perfectly. I dont know whether its better for the car but it sure feels like its breathing and driving healthy. 95 octane made my car feel like it was dying trying to take slow deep breaths when shifting gears

^ by the way, when i say shifting gears, i mean normal ordinary automatic shifting which the car does by itself

I have owned many 523i BMWs 1998 and 2000 and all had a great impulse and geat speed. Now I own a 318i 2003 BMW and I am using 91 gasoline and the car runs like a rocket and I have spend almost 1/4 less money in gasoline in a month.

thare are some point which we forgot about it ,, You may safe some dollar but next year you will pay extra for replacing full fillter and others so it's good to go For 95... I have...