What's the difference between BMW models? (what do all the numbers mean?)?

I'm searching for a used BMW and I see 525i, 325i, 328i, 325i, 318i etc etc. I'm sure it's engine related, but what's the difference?What's the difference between BMW models? (what do all the numbers mean?)?BMW has four primary lines, the 3 Series, 5 Series, 6 Series and 7 Series cars. The first number (as in 325i) represents the model line, the second two numbers (25) represents the the engine displacement, in this case 2.5 liters. A 745 is a seven series car with a 4.5 liter motor.What's the difference between BMW models? (what do all the numbers mean?)?
the first digit always represent the model, as in 3 series, 5 series, etc. in the past 15 years bwm has produced the 1, 3, 5, 6 and 7 series. the last two digits are meant to denote a the grade of the vehicle as compared to the others in its series. often the 30 will have a 3.0 liter engine, but not always. currently the 325 has 2.8 liter engine previously the 545/745 had a 4.4 liter engine. suffice it to say, the higher the number, the bigger, more powerful the engine.



bmw chose to use a different scheme with the Z3/Z4, X3, X5 and earlier the Z1 and Z8. no engine reference except in the accompanying badging on the vehicle.



it's not greek, but it isn't as obvious as it looks.What's the difference between BMW models? (what do all the numbers mean?)?it used to be the series, and engine, and the i denoted injection. A 328i was a 3 series 2.8 engine injected. That has gone away somewhat. for 2007 you have a 328 and a 335 both with a 3 ltr. Totally different motors but same size. Even the outgoing 325 and 330 had the same 3 ltr engine.



I guess it's just good to figure that the series will always be right, but the engine type will just be close.What's the difference between BMW models? (what do all the numbers mean?)?
One of the reasons to use the same engine for 328 %26amp; 335 (also between the 525 and 530) is cost efficiency in manufacturing. It's cheaper to use a computer to control the output (hp) than to actually make a smaller engine.What's the difference between BMW models? (what do all the numbers mean?)?The first number is the series, the second and third number are the engine displacement.



330 = 3 series, 3.0 liter engine

540 = 5 series, 4.0 liter engine.What's the difference between BMW models? (what do all the numbers mean?)?
when the model number starts w/ 5 that means its a 5 series model, 3 is the 3 series model w/ diff engine displacement engine. also, body, trimmings, interiors %26amp; pricing are entirely different.