318is or 325i

[donnyboiler]

I had a consistent 35 mpg from my first is, and 34 from my second. That's averaged out over something like 4 years, and that was back when I was young and drove like an idiot. Mine were both low-mileage engines though - back when there were plenty of those about!

A UK spec 325i had 171 bhp (170 cat I believe) from the factory. The figure of 168 that floats around comes from US spec cars I believe.

Don

[Saga]

I had a consistent 35 mpg from my first is, and 34 from my second. That's averaged out over something like 4 years, and that was back when I was young and drove like an idiot. Mine were both low-mileage engines though - back when there were plenty of those about!

A UK spec 325i had 171 bhp (170 cat I believe) from the factory. The figure of 168 that floats around comes from US spec cars I believe.

Don

My figure of ~30ish combined includes ragging the crap out of it on the B-road bits of my commute, plus I forgot to say mine still has the 316i diff in it, so I suspect it may be "one higher" than the -is LSD.

[timbmw]

chipped 123d M sport engine into an e30... problem solved until you try and drive it LOL

[Morat]

M20s are more than happy with regular unleaded.

[magpie]

get an 'IS' and give it 24v! sorted

[Brianmoooore]

I wouldn't have thought any E30 would be a good choice for someone concerned about petrol consumption.

A relation of mine has just bought a brand new 1.6 Astra turbo, and is currently giving both the dealer and Vauxhall major grief over the somewhat large difference between the quoted overall fuel consumption and the real world one, which he's finding is the low 30s. Not a lot more than you could expect from an iS!

[Huge]

I had a 325 sport a few years ago (until some scumbag stole it..) and still have an iS.
The iS *feels* about 10mpg better than the 325. I remember the 325 being a real guzzler..
I don't use the iS so much these days, but when I used to commute in it (100 miles a day, approx 50:50 country roads and motorway) I could get 40mpg without trying hard at all - on regular unleaded.
I've got a chip in it for 7,000rpm goodness and when it's wound up, it's pretty quick - not far behind a 325 IMO..
However, it doesn't sound good at all - nothing when compared to a 325 (or my old Integra for that matter
Bottom line is that if you need to commute in it, the 318iS is a no-brainer.
cheers

[Brianmoooore]

the 318iS is a no-brainer.
cheers

iS on multipoint LPG would be even better!
There's plenty of multipoint 4 cylinder kit getting on ebay these days, along with semi scrap 4 pot cars with decent kit, which can be relieved of their LPG gear and sold on, or just weighed in.

[Jon_Bmw]

318is with a 3,91 open diff(£40) for commuting I would think would be your best option. With a 4,10 if you get on a motorway, they are far too buzzy for my liking.

Alright its going to be fairly slow, but not horrendously so and it'll have enough to keep up with the flow of traffic.

If fuel isn't a concern, the 325i every time, interestingly I doubt many people with 325s get a combined figure that is much better than I get from my 540i! (23 winter, 26 summer[actual mpg])

[donnyboiler]

I had a 325 sport a few years ago (until some scumbag stole it..) and still have an iS.
The iS *feels* about 10mpg better than the 325. I remember the 325 being a real guzzler..
I don't use the iS so much these days, but when I used to commute in it (100 miles a day, approx 50:50 country roads and motorway) I could get 40mpg without trying hard at all - on regular unleaded.
I've got a chip in it for 7,000rpm goodness and when it's wound up, it's pretty quick - not far behind a 325 IMO..
However, it doesn't sound good at all - nothing when compared to a 325 (or my old Integra for that matter
Bottom line is that if you need to commute in it, the 318iS is a no-brainer.
cheers

There seems to be some disagreement as to what constitutes a car that is "quick" and a car that is "slow". A 318is is not as quick as a 325i, but neither is it "slow".

A 318i is slow (ish). A 316i is just plain slow. Even a 320i has a decent turn of speed when wound up. The 318is is quick enough to be enjoyed. A 325i is still properly rapid today. Want a slow car? My first car was a 1989 Polo 1.3 CL. Now that is slow - it slowed down up hills, whichever gear it was in. And that was the quicker one! Anyone driven a Polo formule e? Cars like this make even the 316i feel quite poky.

No-one ever claimed the Mk. 2 Golf GTi was slow. Even in 8v form, where it isn't particularly quick, it is still fast enough to have a LOT of fun in. The 318is is quicker (and in my opinion, more fun).

I think part of the problem is down to people moving on to faster cars (or doing cool engine swaps) and then dissing the cars they moved on from. I have had several cars quicker than my old 318is's, but hardly any I've enjoyed driving as much. Get in a 318is, point it at a fun back road, keep the revs up, and see if you still think it's slow.

The other part of the problem is 318is owners constantly claiming that their cars are as nearly as quick as 325is. THEY ARE NOT. On the right road (a very twisty one) they might pull away here and there, but on the straights, the 325i absolutely obliterates the 318is. It's not even in the same league, chipped or not. I've owned them all, and a chipped 318is is still my favourite, for all the reasons written here and more. But it is significantly slower than a 325i. Any 325i.

Maybe the figures should be written on a banner at the top of the forum to stop so many boring posts...

The 318is: quickish, fun, reliable, great package, economical, slower than 325i.

Move on.

[Felix79]

^^WoW ^^

If memory serves me right , some of the 2.7 owners get a very good mpg due to the engine having greater torque and this allows it to be a great cruiser on the motorway.

At the end of the day we buy these cars with our hearts and not out heads , it is very raley the two ever agree on the same thing.

[Royalratch]

I've owned both and for motorway commuting you're better off with the 6 and just pay the fuel costs - you cannot have MPG AND performance. You must choose.

In every other way, town driving, throttle response and handling the 318iS is superior.

[Jon_Bmw]

A bit of a confession here.

I quite enjoyed the 318is and giving it a good spanking on a B road. It was a good neutral handling car, it just needs 30-40bhp more IMO. If it had circa 180bhp it would be a real cracker*. It just didn't have enough poke to stop me swaying to something that did.

*hopefully not at cracking heads

[dimebag_from_hell]

And tbh, even with poor mpg, the m20 doesn't give great performance.

You could get better mpg out of a 3.2l e36 m3 evo.

[Saga]

Jon_BMW does sum up one feature of the -is experience - even when you're caning it down a B road, it will always occur to you that it would be really much better with 180hp! That ties in pretty well with what's been said about the 325 killing it in a straight line.

Don't get the hate for the -is's motorway performance though. My wife's Berlingo struggles to get past 70 in top if there' s a slight rise. My is/touring will happily keep pulling up to ~100 - don't know how many of you would want to go faster on a public road, if only for licence preservation.

[Royalratch]

I've managed 130mph in Germany in me iS. Not even downhill - Autobahn between Koln and Nurnberg.

[donnyboiler]

My first iS was a quick one. It used to bounce off the rev limiter easily in 5th, on the flat with no tailwind. That equates to 20.7mph (per 1000rpm in 5th) x approx 6500 rpm which is almost 135 mph. That was a good M42 in that one. It got 35mpg all day long too.

My second iS was superchipped and revved to around 7000 rpm. Oddly it didn't go so well in 5th, running out of steam before the redline like they are supposed to. The book top speed of 127mph equates to around 6100 rpm with a standard gearbox and diff.

How do you guys compensate for speedo inaccuracy when measuring top speed? Or do you have another way of measuring actual speed?

Don

[pony]

I wouldn't have thought any E30 would be a good choice for someone concerned about petrol consumption.

the e30 is my favourite car, im just trying to get the most fuel economic one.

Surely that means you want the BMW E30 316i model.

[pony]

I had a 325 sport a few years ago (until some scumbag stole it..) and still have an iS.
The iS *feels* about 10mpg better than the 325. I remember the 325 being a real guzzler..
I don't use the iS so much these days, but when I used to commute in it (100 miles a day, approx 50:50 country roads and motorway) I could get 40mpg without trying hard at all - on regular unleaded.
I've got a chip in it for 7,000rpm goodness and when it's wound up, it's pretty quick - not far behind a 325 IMO..
However, it doesn't sound good at all - nothing when compared to a 325 (or my old Integra for that matter
Bottom line is that if you need to commute in it, the 318iS is a no-brainer.
cheers

There seems to be some disagreement as to what constitutes a car that is "quick" and a car that is "slow". A 318is is not as quick as a 325i, but neither is it "slow".

A 318i is slow (ish). A 316i is just plain slow. Even a 320i has a decent turn of speed when wound up. The 318is is quick enough to be enjoyed. A 325i is still properly rapid today. Want a slow car? My first car was a 1989 Polo 1.3 CL. Now that is slow - it slowed down up hills, whichever gear it was in. And that was the quicker one! Anyone driven a Polo formule e? Cars like this make even the 316i feel quite poky.

No-one ever claimed the Mk. 2 Golf GTi was slow. Even in 8v form, where it isn't particularly quick, it is still fast enough to have a LOT of fun in. The 318is is quicker (and in my opinion, more fun).

I think part of the problem is down to people moving on to faster cars (or doing cool engine swaps) and then dissing the cars they moved on from. I have had several cars quicker than my old 318is's, but hardly any I've enjoyed driving as much. Get in a 318is, point it at a fun back road, keep the revs up, and see if you still think it's slow.

The other part of the problem is 318is owners constantly claiming that their cars are as nearly as quick as 325is. THEY ARE NOT. On the right road (a very twisty one) they might pull away here and there, but on the straights, the 325i absolutely obliterates the 318is. It's not even in the same league, chipped or not. I've owned them all, and a chipped 318is is still my favourite, for all the reasons written here and more. But it is significantly slower than a 325i. Any 325i.

Maybe the figures should be written on a banner at the top of the forum to stop so many boring posts...

The 318is: quickish, fun, reliable, great package, economical, slower than 325i.

Move on.

Nicely put together post.
As you have owned them both how does the sound compare between a 325i Sport and 318iS? I find the BMW E30 325i (mine has no catalytic convertor noticeable FAR LOUDER than my BMW E46 323Ci Coupe) especially when through narrow streets, bridges and narrow tunnels below 70mph.

Separate point why does a BMW E46 M3 straight six have what is described as a "raspy" sound?
Is that a characteristic of it having a normally aspirated straight six or the high revolution concept?

[Royalratch]

There is all kinds of sub £500 scrap faster in a straight line than a 325i - so what? If that's the only measure of a car that 325i owners can understand then...

318iS owners are enlightened - both cars cost the same these days so there's no point giving it the biggun' being a 325 owner at all. If sporting prowess is what draws you to a BMW then the 318iS is the pick of the bunch - all else being equal - looks, spec etc etc.

One of us pays more at the pump to be a slower, less enjoyable, mechanically inferior car. You do get to say your engine is bigger with 2 more cylinders - big deal.

Just in case you didn't know...

[youtube][/youtube]

[jann]

Rofl great vid.

[e301988325i]

My first iS was a quick one. It used to bounce off the rev limiter easily in 5th, on the flat with no tailwind. That equates to 20.7mph (per 1000rpm in 5th) x approx 6500 rpm which is almost 135 mph. That was a good M42 in that one. It got 35mpg all day long too.

My second iS was superchipped and revved to around 7000 rpm. Oddly it didn't go so well in 5th, running out of steam before the redline like they are supposed to. The book top speed of 127mph equates to around 6100 rpm with a standard gearbox and diff.

How do you guys compensate for speedo inaccuracy when measuring top speed? Or do you have another way of measuring actual speed?

Don

Sat nav or timed distance is the only true measure. Tyres slip against the surface they drive on, quite considearbly at high loads and speeds, circa 5%, which makes it very difficult to get an accurate fix on top speed, my E30 speedo is at least 5mph optimistic after 85mph on the satnav.

[Royalratch]

Speedos are generally designed to be optimistic as a little safety precaution I thought...

[e301988325i]

Speedos are generally designed to be optimistic as a little safety precaution I thought...

It's a legal requirement to never read under on the speedo, but in truth it also has to cover other changes such as tyre wear or wheel / tyre comination changes.

The video is great, especially about the S14 being a cheap copy!

[donnyboiler]

Nicely put together post.
As you have owned them both how does the sound compare between a 325i Sport and 318iS? I find the BMW E30 325i (mine has no catalytic convertor noticeable FAR LOUDER than my BMW E46 323Ci Coupe) especially when through narrow streets, bridges and narrow tunnels below 70mph.

Thank you. I LOVE the sound of both cars. A 325i is objectively the better noise, by far. It's quieter when you're not pushing, and sceaming, barking loud when you are. I've always loved the sound of the M42 at high revs though - it's a metallic growl that sums up everything I love about revvy 16v screamers. My 325i wasn't a sport though.

Separate point why does a BMW E46 M3 straight six have what is described as a "raspy" sound?
Is that a characteristic of it having a normally aspirated straight six or the high revolution concept?

I think that's the induction/exhaust part of the equation. The engine itself is a development of the E36 M3 evo's engine, which was a development of the non-evo, which was essentially a bored and stroked M50. And the M50 I think I read is more or less an M20 with a 24v head, knock control allowing for higher compression ratio and (from '92 on) vanos. I'm sure someone more technically knowledgeable can jump in here and sort this lot out.

[donnyboiler]

One of us pays more at the pump to be a slower, less enjoyable, mechanically inferior car. You do get to say your engine is bigger with 2 more cylinders - big deal.

Slower how? The 325i?

Great vid!

[Andyboy]

He's just kidding. The 325i is blatantly much, much faster. 136 bhp v 171bhp, notwithtanding an extra chunk of torque..............no - brainer! The 325i is something like 6-7 seconds faster to 100....there's just no comparison.

Weight distribution? The extra weight of the 325i engine is equalled out by a sodding great battery under the hood of the iS.

My 325i Touring was also very good on fuel once it had a 3.64 diff shoved up it (saloon diff). It would easily do mid 30's on a steady run.

[Saga]

Though again this may not be gospel (cf the 168/171bhp figure), John Burns' site says M20 117kg, M42 ~100kg. The four is also further back, which helps the car not handle like a VW ...

Personally, I think the ticket is to just drop an SR20DET into a 316i. That will see off either of them.

[Andyboy]

17 Kilos..............what does an E30 battery weigh....?

The iS engine is not further back - there's the same small gap between the back of the head and the bulkhead. In reality there's no difference in handling. The M20 is not a heavy unit - check out an M30 or an S50 if you want to see a heavy motor.
The 318iS understeers like any other regular E30.

[MrBenn]

Slightly off topic I know. Here's an M30 powered e30 beating an e30 M3 in the wet round Brands Hatch.........

[Saga]

The iS engine is not further back - there's the same small gap between the back of the head and the bulkhead. In reality there's no difference in handling. The M20 is not a heavy unit - check out an M30 or an S50 if you want to see a heavy motor.
The 318iS understeers like any other regular E30.

It's further back because it's shorter.

But yeah, a 325 could seem to be understeering more because its average corner entry speed is higher.

e: not that I'd know - if you're getting understeer you're driving much harder than me. I only get a bit of push from the back when on the power.

[tim_s]

m42 is furthest back of the lot, s14 included (only just though). I've measured before. The m20 is a bit longer - you get a better idea when you take the fan cowling off an IS, it sits a fair old way from the front. The engines have the same bore spacing and the IS has 2 cylinders less... it's thus unsurprisingly a smaller engine.



The weights quoted above are bare weights - ancilliaries, 'box, diff etc all lighter on the IS, and overall the car at 1125kg is a good deal lighter than a 325 - isn't the 325 2 door over 1200kg iirc? They don't handle the same, the IS feels more nimble, but it's hardly the end of the world either way. I still like the 318is, but there's nought wrong with the 325, which is undoubtedly faster. I never got anywhere near the same fuel economy as the IS out of the m20 though, and it really wasn't worth it for the performance difference. sounded nice though At slower speeds it didn't make much odds, at silly speeds the m20 was quicker. On track there's not a lot in it if you rag the m42 to within an inch of its life.

[Saga]

God that's a clean is. Mine doesn't look like that!

How not to do it...

[jann]

Looks like its spat out old coolant.

[tim_s]

God that's a clean is. Mine doesn't look like that!

Looked even cleaner after it had the 2.1 dropped in!