Poor mpg..

[Smithy89]

When my engine was changed from a 2l to a 2.5s a couple of bits from the old engine we're used, as it didnt come with these parts-the inlet manifold, idle control valve and throttle body. It seems to run fine just very juicy would this be why?

[kam-325i]

The inlet manifold and Throttle body are smaller on the 2.0l than on the 2.5l, so these will be restricting the engine.

[Grrrmachine]

M20s are generally juicy, but a 325i should return the same mpg as the original 2.0. Bear in mind, however, that by using the 2.0 throttle body and inlet, you are severely throttling the 2.5 engine.

If you're getting bad mpg, check your fuel lines, TEST your blue temp sensor, and send your injectors off to Injectortune for a refurb.

[Smithy89]

Ok will change that soon as then, how about the fuel pump-in tank type, not been changed. Sufficient enough?

[kam-325i]

pump should be ok, required pressure is the same, although volume is a bit more on the 2.5l

[Smithy89]

Fuel lines and injectors are getting done this week, have tested the temp sensor hot and cold seems to be fine. Hopefully after all this I will be getting more than 60 miles from £20! What should I be looking for from a 2.5s?

[Grrrmachine]

there's no appreciable difference in mpg between a 2.0 and a 2.5. No such thing as a 2.5s, unless you mean the sport which is still just a 2.5 engine.

MPG will very rarely get over 25.

[kam-325i]

£20 is around 13 liters = 2.85 Gallons,

expect around 30-65 Mpg depending on driving.....

[Smithy89]

Yes I mean sport. I'll see how I get on after I have changed and refurbished the parts, cheers!

[kam-325i]

Do you mean a 2.5l Sport engine ?

[Grrrmachine]

The sport engine is no different from any other 2.5 engine, so he just means M20B25

Calling it a Sport when the car didn't leave the BMW factory as a Sport upsets a few people on here

[Smithy89]

I'm new to here and to e30's as you can probally tell..

[Smithy89]

I got myself a year ago and old convertible which needed a lot of attention, head gasket went not long after I got it so got this engine off a friend, replaced existing suspension with a decent set of coilovers, and had it re sprayed alpina blue as it was a bit of a rust bucket. Fair to say I rescued an e30? Think I will stick with them too!

[Smithy89]

I've still got a lot to learn with the engine side of things yet but I'm getting there