Is m30 swap worth it?

[Red88]

I'm starting to think there is something wrong with my car... I have a 2.93 and I barely make 15mpg

[CorvallisBMW]

Gas is the biggest downfall in the m30 vs 2.7i debate. m30s use a lot of fuel. M50s use the least fuel. So are you driving 100 miles per day, or 10?

If this is a stop-gap motor to have fun with while to prepare for a V8 swap, then just get a chip, 3.25 lsd, and call it a day. You'll be surprised by how much fun an eta can be with shorter gearing. We ran one in LeMons and ChumpCar with a 3.73 and were just as quick as 98% of the other cars on track. Save you blood, sweat, tears, and money for the big guns.

[LowR3V'in]

My stock m30 got about the same mileage as my turbo m20.
My turbo m30, forget about it.
Like 150 miles per tank. Too much fun $

With the forum hype about m50s you'll be disappointed when you're done.
Little baby 2.5L feels like a 4cyl. If you're keeping it stock, m50 is not worth it for power.

[Batz]

Gas is definitely a big deal to me, i drive a lot, around 100 (sometimes more) miles a day, a lot of the time in the city as well, so i guess no m30 for me. M50s are just over rated, and honestly dont see why people like them so much (unless boosted). They dont make that much power so i agree with LowR3V they're definitely not worth it for power, maybe just looks...

People suggesting to keep my eta, hehe, it is fun, especially when it rains with my 2.93lsd and etc,. but the thing is, the engine eats oil, everything is leaking (and i mean everything , except the coolant, and im sure that one will start soon). So i will be pulling the engine out anyways, i just dont see the point of putting money into this one just to make it reliable when i can put a bit more money and make it also much faster. I dont know... call me stubborn i guess.

[lukeADE335i]

I'm starting to think there is something wrong with my car... I have a 2.93 and I barely make 15mpg

Are you running an O2 sensor? Many people say unplug them, but I found with my swap, a new O2 made a bigger difference to drivability & economy than I had expected.

[CorvallisBMW]

Gas is definitely a big deal to me, i drive a lot, around 100 (sometimes more) miles a day, a lot of the time in the city as well, so i guess no m30 for me. M50s are just over rated, and honestly dont see why people like them so much (unless boosted). They dont make that much power so i agree with LowR3V they're definitely not worth it for power, maybe just looks...

People suggesting to keep my eta, hehe, it is fun, especially when it rains with my 2.93lsd and etc,. but the thing is, the engine eats oil, everything is leaking (and i mean everything , except the coolant, and im sure that one will start soon). So i will be pulling the engine out anyways, i just dont see the point of putting money into this one just to make it reliable when i can put a bit more money and make it also much faster. I dont know... call me stubborn i guess.

m52 then? Good power, torque, and fuel economy.