03 2.5 V 07 2.5

C

captain caveman

Member
Currently have a 03 2.5 witch i really like and cant really fault it.
But ive been offered a 07 2.5 with really low mileage, The only niggle is the 07 is 177bhp and no sport button.

Whats the difference in the 2 engines? Why is the later car a lower bhp and is there a way of getting it up to the 190 of the older 03 car.
 
The face-lift has the N52 engine, so a lot lighter due to its Magnesium alloy block, and prone-to-fault components have been improved, such as VANOS and DISA valve. Power delivery is more smooth too. Looking at 0-60mph there's only a 0.1s difference between the two and you can get the 177hp mapped to around 190hp for £250.
BMW reduced parasitic losses on the N52 engine for better mpg and emissions. This was partly achieved with an electric water pump that has been reported to fail between 60-100k miles, it costs around £205 and is a simple DIY to replace it. VANOS and DISA should not give you any problems like in the S54.

So I bet the facelift would out perform the older version even with less power due to lighter front end, better power delivery. This is my opinion, not fact.

I have a 07 E85 2.5i and I love it. Sport button only sharpens the throttle response (throttle by-wire) and makes the steering heavier, so no real performance gains with the button on or off, just more fun.
 
captain caveman said:
How do you find the 6 speed box over the 5 speed if you have had one of course.
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I've not driven the 5-speed gearbox, but I can give you my thoughts on the 6-speed. Coming from an MX5, which is known to have one of the best shifts, I was slightly disappointed with the shift feel, but after adding a weighted shifter (ZHP) and changing the oil in my gearbox, I can say if feels amazing and I dare say better than my MK2.5 MX5. 1st-2nd is no longer notchy and all gears go in, up or down, very smoothly - I always rev match when going down the gears, so I don't know how it feels otherwise. I really dislike the reverse position as I've put into reverse a few times when I wanted 1st (always happens when trying to leave in a hurry and trying to just throw 1st a bit enthusiastically). Cruising in 6th at 72mph on the motorway with the engine just below 3K also feels very nice (vs MX5 3750rpm at 70...)
 
Has to be the newer car, if you have a good deal on the table, go for it. Lower miles, reduced chance of engine niggles and similar performance. What are you waiting for. :)
 
I'd be tempted by the later car with the low mileage.

Definitely worth trying it, then you'll know how it compares to yours.

The N52 engine in the facelifts does like to rev more than the earlier engine - but if you let it you get more fun and more sound-track!

I don't know what changes BMW made to the 2.5i to give it only 177 bhp, but the Si version of the same engine is 218 bhp and I had one of those in a 325i and liked it.

I've only had one 5 speed BMW, but I've had six 6 speed ones which were all better - although some I've had were better than others. But as has been said, getting the transmission oil changed and fitting a ZHP gear-knob definitely improves things!

Goog luck deciding. :thumbsup:
 
Power to weight ratio....

2003–2005 2.5i 189bhp
Power to Weight Ratio 141.58 BHP per tonne

2006–2008 2.5i 174bhp
Power to Weight Ratio 129.38 BHP per tonne

2006–2008 2.5si 215bhp
Power to Weight Ratio 158.1 BHP per tonne

See if you can get a 2.5si as that'll be quicker.

Guy at work has a 1.8 Mazda MX-5 NB with throttle bodies, stainless exhaust, remap and cat deleted. That's been tested to 145bhp per ton at the rear wheels.
 
I have a z4 2.5i 177bhp and honestly the performance is a abysmal. I have had 7 z4s now and I knew this from the get go. The pre facelift one is much quicker. They made this in the Facelift to replace the old 2.2 m54. The 2.0 4 pot feels quicker due to it being a lighter engine,

I honestly think you'd be disappointed going from the pre facelift car performance wise and the 5 speed box is a slicker unit imo. As above you'd be best holding out for an si version with 218bhp.
 
Why did they have it sitting at 177? Seems really strange. I have a 2.5si and I don’t think that’s mad quick so can only imagine the i is woeful
 
Cribert said:
Why did they have it sitting at 177? Seems really strange. I have a 2.5si and I don’t think that’s mad quick so can only imagine the i is woeful
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As I said, the 2.5i 177 is the replacement for the prefaclift 2.2i 170bhp. Probably for insurance reasons or whatever
 
Emissions?

Probably a team of spotty yoofs found a niche within the niche that statistically showed demand for the less powered car while confusing your average buyer that the car was actually faster.
 
skelters said:
Power to weight ratio....

2003–2005 2.5i 189bhp
Power to Weight Ratio 141.58 BHP per tonne

2006–2008 2.5i 174bhp
Power to Weight Ratio 129.38 BHP per tonne

2006–2008 2.5si 215bhp
Power to Weight Ratio 158.1 BHP per tonne

See if you can get a 2.5si as that'll be quicker.

Guy at work has a 1.8 Mazda MX-5 NB with throttle bodies, stainless exhaust, remap and cat deleted. That's been tested to 145bhp per ton at the rear wheels.
Click to expand...

Good power-weight facts :thumbsup:
 
I can see why they made it as a replacement for the pre-facelift 2.2i and at least it is a straight 6.

Coming from something "normal" like a 1.6/1.8 Focus/Astra/Golf, etc. it would probably feel quite exciting - but from a pre-facelift 2.5i probably not!

Still if it's a good deal the OP might as well try it first. :thumbsup:
 
Ewazix said:
Good power-weight facts
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They would be if they were correct! The N52 is 15kg lighter, therefore, the power to weight is actually 139.76 bhp per ton. The M54 at 1260kg has a bhp per ton of 150. The reason the lower power 2.5 accelerates just 0.1 sec to 60 slower is the closer ratios of the 6-speed versus the 5-speed box, which will also be of benefit above 60. If you 177 feels abysmally slower than a 189 then you have something wrong with your engine and needs checking.
The choice between a low mileage 177 and a high mileage 189 is really quite easy.
 
Davz said:
Ewazix said:
Good power-weight facts
Click to expand...
They would be if they were correct! The N52 is 15kg lighter, therefore, the power to weight is actually 139.76 bhp per ton. The M54 at 1260kg has a bhp per ton of 150. The reason the lower power 2.5 accelerates just 0.1 sec to 60 slower is the closer ratios of the 6-speed versus the 5-speed box, which will also be of benefit above 60. If you 177 feels abysmally slower than a 189 then you have something wrong with your engine and needs checking.
The choice between a low mileage 177 and a high mileage 189 is really quite easy.
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You say "the N52 is 15KG lighter" but the N52 is apparently 10Kg heavier than M54 on most data sheets :? also are you mixing apples and oranges when doing power calculations, BHP and HP figures are different - the facelift 2.5i is 174bhp / 177 hp.

https://www.carleasingmadesimple.com/data/bmw/z4/kerb-weight/
https://www.autoevolution.com/cars/bmw-z4-roadster-e85-2006.html#aeng_bmw-z4-2006-25i

But it's all a bit academic anyway I've had low mileage dogs and high mileage flyer, also anybody who has driven two identical cars back-to-back will often find one is a peach. When it comes to older cars condition, history and how it drives is far more important than stat's or pre-conceptions, let the test drive decide.
 
Weights were taken from the Wikipedia page on the E85's.

Will check the weight etc from the Z book when I can be bothered.
 
Ewazix said:
https://www.carleasingmadesimple.com/da ... rb-weight/
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The website you have listed only states the kerbweight of the smg and auto gearboxes, those models are much heavier hence the slower acceleration times for those zeds. The N52 uses an alloy including magnesium which reduces the weight by 15kg, this takes the weight down to 1245kg as opposed to the older m54 at 1260kg. The n52 has 177ps or 174.5 bhp, I calculated the bhp per ton using 174 for simplicity. The older 2.5 does have 15lbft of torque more which gives it as good acceleration as the newer 6 speed box. The N52 could be chipped, as someone has already said, to give comparative bhp to the m54, if outright performance is your goal.
 
Ewazix said:
https://www.carleasingmadesimple.com/da ... rb-weight/
Click to expand...
The website you have listed only states the kerbweight of the smg and auto gearboxes, those models are much heavier hence the slower acceleration times for those zeds. The N52 uses an alloy including magnesium which reduces the weight by 15kg, this takes the weight down to 1245kg as opposed to the older m54 at 1260kg. The n52 has 177ps or 174.5 bhp, I calculated the bhp per ton using 174 for simplicity. The older 2.5 does have 15lbft of torque more which gives it as good acceleration as the newer 6 speed box. The N52 could be chipped, as someone has already said, to give comparative bhp to the m54, or you can fit an inlet manifold from an e46 to provide Si bhp level of 215bhp, if outright performance is your goal.
 
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