E89 28i mpg Manual vs Auto

[mudmonkey]

I'm in the market for a new car and am considering a 28i. I'm looking for something with a decent amount of power that isn't too terrible on fuel economy either, and it seems to fit the bill.

I know the whole 'mpg question' is highly subjective based on driving styles etc, but having poked around these forums a fair bit, the general consensus seems to be that the 28i only returns around 30mpg on average, a fair bit less than quoted (to be expected).

It seems the majority of 28i's around have the auto box, so my question is, does anyone here have a manual, and if so is there a marked improvement in mpg?

I usually check 'real mpg' figures on Honest John before I make a purchase just so I know what I'm getting myself into, and the auto is quoted as 29.4 mpg average whereas the manual is 37.1 mpg average.

Is anyone able to shed any light on this?

 

[matsmith749]

On the older ones with a 6 speed box I'm not 100% sure - but the newer cars with the 8 speed box are more economical (any engine) versus the same engine with a manual.

In the good old days with 3 speed auto gearboxes it was the other way round.

I doubt the dirrefernce is huge, if you are getting 30 mpg with the auto I'd be expecting high twenties with the manual.

 

[Pondrew]

You should get at least 35mpg average on any manual N20 engine. Easily. Depending on journeys and the way you drive.
BTW the smart money would buy a cheaper 18i, or 20i and a £300 remap, as the engines are all identical.

Weirdly our previous N20 car, a remapped 18i running 270bhp, did an average of 39mpg over 6k miles, whilst the standard 20i we have now does around 36mpg. Same journeys. Both manual.

 

[mudmonkey]

Yeah I was considering the remap route, as you say it would be significantly cheaper. There seemed to be a bit of disagreement as to whether the engines are completely identical, some people with 20i's had engine failures after a remap to 270bhp+ iirc, which put me off a bit.

Haha, that's pretty weird. How long/how many miles did you put on the 18i after the remap?

 

[Pondrew]

Haha, that's pretty weird. How long/how many miles did you put on the 18i after the remap?

6k. Had it done at 25k miles when I bought it. It is now owned by another regular forum member.

There seemed to be a bit of disagreement as to whether the engines are completely identical, some people with 20i's had engine failures after a remap to 270bhp+ iirc, which put me off a bit.

The N20 (the same age) are identical internally. There was a rumour that the 28i has 'strengthened' pistons, but I have never seen any evidence to back this up.
Funny you should mention the remapping issues; I have been looking at remapping our latest 20i but there is a 'warning' on one major chip installers website, but only for the 20i, not the 18i (didn't check the 28 tbh as it's not really worth doing). I keep intending to ask them why but haven't got round to it yet.
The same warning appears for the later B48 engine too, but haven't seen any evidence on BMW forums of failures. Coolant leaks on the B48, yes!

 

[Silverstar]

As someone said the new ZF8 autos are fractionally more economical than the manual. You could go the 18i 20i route and remap but the 28i will always be more sought after and hold its value better IMHO, just because it was the top of the range of the 4 pots and less of them made and not everyone wants to remap or will want to buy a reamapped car further down the line.

 

[mudmonkey]

The N20 (the same age) are identical internally. There was a rumour that the 28i has 'strengthened' pistons, but I have never seen any evidence to back this up.
Funny you should mention the remapping issues; I have been looking at remapping our latest 20i but there is a 'warning' on one major chip installers website, but only for the 20i, not the 18i (didn't check the 28 tbh as it's not really worth doing). I keep intending to ask them why but haven't got round to it yet.
The same warning appears for the later B48 engine too, but haven't seen any evidence on BMW forums of failures. Coolant leaks on the B48, yes!

Interesting. Yeah I'm always a bit wary of remaps personally. Hear too many horror stories, it's all fine....until it's not.

 

[mudmonkey]

As someone said the new ZF8 autos are fractionally more economical than the manual. You could go the 18i 20i route and remap but the 28i will always be more sought after and hold its value better IMHO, just because it was the top of the range of the 4 pots and less of them made and not everyone wants to remap or will want to buy a reamapped car further down the line.

You make a very good point. Trying to resell a remapped car does limit the audience somewhat.

 

[Pondrew]

Trying to resell a remapped car does limit the audience somewhat.

That is true. People generally think a remapped car has been thrashed and is only for 'boy racers' IME.
It's a shame, as the N20 is a much better engine with a remap in every department; especially the vast improvement in low down torque.

 

[DonDon]

I have seen claims that an original 28i has bigger brakes than the 18i or 20i. Don't know if it is true.

 

[B21]

I have seen claims that an original 28i has bigger brakes then the 18i or 20i. Don't know if it is true.

28i had 330mm front brake as per 30i..the 18i and 20i had 300mm as per 23i..

 

[Fady]

As someone said the new ZF8 autos are fractionally more economical than the manual. You could go the 18i 20i route and remap but the 28i will always be more sought after and hold its value better IMHO, just because it was the top of the range of the 4 pots and less of them made and not everyone wants to remap or will want to buy a reamapped car further down the line.

I concur with the your statement on remapping. I have the 28i manual and would never have been knowingly interested in say a 20i remapped car. Rightly or wrongly remapping to me has negative connotations around previous ownership and is also something to factor in with insurance.

No idea on fuel economy as have not owned the car long so not many miles done (keep meaning to do my intro post but not got around to it!). Also mpg not a consideration as is effectively a weekend car. Wanted something with poke but considered the 3.0 versions unnecessary for my own use case as already have a larger engined car.