subyrex 0 Report post Posted August 8, 2011 Hi Guys, Can any of you tell me what type of gas the M50 engines are designed to run on ?. Also the fuel efficiency, if possible. Thanks. 1991 e34 520i, 190k, M50b20 Quote Share this post Link to post Share on other sites
*Glenn* 854 Report post Posted August 8, 2011 95, 96 or 98...just don't use 91 Quote Share this post Link to post Share on other sites
subyrex 0 Report post Posted August 8, 2011 I Put $30 91 in it yesterday. Any reason for not using 91 ? Cheers Quote Share this post Link to post Share on other sites
oscar90 0 Report post Posted August 8, 2011 cause 91's sh*t.. use 95.. it makes a difference Quote Share this post Link to post Share on other sites
BM WORLD 1283 Report post Posted August 8, 2011 m50 engines are high compression engines and should be run on hi octane gas , it will want to ping and knock. then the knock sensors will retard the timing , then you will have to apply more gas to make the car move and use more of it. dont be a tight A$$ and use 95 or higher , will use less of it so works out about the same in $$$ Quote Share this post Link to post Share on other sites
westy 614 Report post Posted August 8, 2011 Hi Guys, Can any of you tell me what type of gas the M50 engines are designed to run on ?. Also the fuel efficiency, if possible. Thanks. 1991 e34 520i, 190k, M50b20 It's designed to run on fuels as low as 91 RON. It's optimised to run on fuels 95+ RON. As for economy, in this case you probably want to run it on 95+ with a small engine in a large car. It's going to be working pretty hard and want all the spark advance it can get. But you'll have to test it to find out for sure. PS. 91 isn't 'sh*t'. Just has less/different additives. Quote Share this post Link to post Share on other sites
No name user 379 Report post Posted August 8, 2011 PS. 91 isn't 'sh*t'. Just has less/different additives. agree ive done many n/a and turbo setups using 91 without an issue Quote Share this post Link to post Share on other sites
oscar90 0 Report post Posted August 8, 2011 was on my phone, so sh*t wasn't the right way to put it but the quickest. When i first got my M50b20 i ran it on 91 no problems, seemed to run fine, then changed to V Power/95 octane and there was a noticable difference for sure, you can run it on 91 as others have said but 95 is definetly the better choice from my personal experience...and thats all it is, personal experience Quote Share this post Link to post Share on other sites
_ethrty-Andy_ 2132 Report post Posted August 8, 2011 being the proud owner of a 520i, save the coin and wait for a V8, or at least a 2.5L. the 2L unit has no balls at all with this weight, and i even have the M52 version with vanos lol. mind you i use 91...... Quote Share this post Link to post Share on other sites
subyrex 0 Report post Posted August 8, 2011 It's designed to run on fuels as low as 91 RON. It's optimised to run on fuels 95+ RON. As for economy, in this case you probably want to run it on 95+ with a small engine in a large car. It's going to be working pretty hard and want all the spark advance it can get. But you'll have to test it to find out for sure. PS. 91 isn't 'sh*t'. Just has less/different additives. Thanks for clearing that up, will try 95 Ron again to see if I notice any difference in mileage. Quote Share this post Link to post Share on other sites
