[THE JEDI]

Okay here we go fellas....the reason the of the 218 and 215 rating.....is he available gas octane rating.......m5 507(every place else) 500 in the u.s......don't read to much into it

[RPM90]

Originally Posted by JamieA

I have thought the same thing. It would have been interesting to hear why they made the decision and how. They probably did research and used focus groups and the like becauase this would have been a crucial decision for them. Probably nearly as crucial as styling.

My guess is that (probably until recently when fuel prices hiked) people in the US did not like small cars (hence no 1 Series) or small engines. I Think the detuned 3.0 is just a "size" thing, as there appears to be little gain in having it and having another engine variation beyond that. North America is a big market for BMW so there are the economies of scale to do bespoke models for that market.

Same in reverse for the Euro market. They have an engine that still delivers the same goods, but is a smaller capacity engine and therefore more palatable in markets where smaller engine sizes are preferred due to fuel costs, taxes and the like.

The issue was, supposedly that the 2.5 liter couldn't meet US emissions regs in it's current state. So, I don't agree it's a "size" think with the US because BMW doesn't even advertise that the 325i has a 3.0 engine and most BMW buyers have no clue that the 325i has 3.0 engine.

Yes, for the Euro market it makes sense to have the smaller engines due to the taxing issues as some countries make you pay more if your engine is bigger. Wonder how that would affect measured penis size it were taxed based on a size scale?

Still, it seems that that US 325i 3.0 has been under rated to keep the 330i folks happier. The only 325i manual test I've read is from Car&Driver and it did 0-60 in 6.1 and the 1/4 in nearly the same time as the 330i with the 330i having the faster trap speed. I'm sure the 330i is faster in top speed and getting there as well.
Still, the 325i seems faster than it's published power numbers suggest. Also, I believe the new 3.0 engine is lighter or weighs as much as the former 2.5 engine.

I think the 3.0 liter in the 325i and 330i makes sense. You have less engines to change the production line thus streamling it for the US run. Going the Nissan model is a good move. Nissan uses that excellent 3.5 V6 in nearly all their cars/trucks yet in various states of tune with either more HP or more torque. They even carry it into the Infiniti line with the G35 coupes and sedans. Great idea.
One great engine, low retooling costs, lower per engine costs, and everyone is happy.

T

[RPM90]

Originally Posted by jhbodle

Here's the US 325i torque curve to compare the low end torque:

That's a marketing dyno print, not a very good real dyno print.
The curve looks almost identical between the 2.5 and US 3.0 engines. That makes me very suspicious of it's accuracy.

T

[RPM90]

Originally Posted by THE JEDI

Okay here we go fellas....the reason the of the 218 and 215 rating.....is he available gas octane rating.......m5 507(every place else) 500 in the u.s......don't read to much into it

The difference is in "bhp" vs. "hp".

US fuel octane is about the same as the Euro or Japanese fuel.
In the US we use a RON+MON/2 to get our octane number.
The Euro market uses only RON, which is a higher number than MON. Thus, our US octane is an average of the 2 methods used to test a fuels octane. Naturally, the averaged number will be less mathematically. In reality it's possible that some US fuels have a higher RON than some Euro fuels.
Overall, the difference is due to testing method not capability.

T

[voltron1011]

Originally Posted by RPM90

The difference is in "bhp" vs. "hp".

Us fuel octane is about the same as the Euro or Japanese fuel.
In the US we use a RON+MON/2 to get our octane number.
The Euro market uses only RON, which is a higher number than MON. Thus, our US octane is an average of the 2 methods used to test a fuels octane. Naturally, the averaged number will be less mathematically. In reality it's possible that some US fuels have a higher RON than some Euro fuels.
Overall, the difference is due to testing method not capability.

T

You are absolutely correct...

:mad: It reminds me of one of my cousins in Germany who used to brag how high the octane numbers were compared to the US.

[THE JEDI]

HEY AINT THAT WHAT I SAID....BUT THANK YOU FOR THAT VERY SCIENTIFIC, EXPLANATION.... NOW WE KNOW WHY BMW OWNERS ARE BETTER....WE BE SMARTER THAN THE AVERAGE BEAR :rocks:

[JamieA]

Originally Posted by RPM90

The issue was, supposedly that the 2.5 liter couldn't meet US emissions regs in it's current state. So, I don't agree it's a "size" think with the US because BMW doesn't even advertise that the 325i has a 3.0 engine and most BMW buyers have no clue that the 325i has 3.0 engine.

Yes, for the Euro market it makes sense to have the smaller engines due to the taxing issues as some countries make you pay more if your engine is bigger. Wonder how that would affect measured penis size it were taxed based on a size scale?

Still, it seems that that US 325i 3.0 has been under rated to keep the 330i folks happier. The only 325i manual test I've read is from Car&Driver and it did 0-60 in 6.1 and the 1/4 in nearly the same time as the 330i with the 330i having the faster trap speed. I'm sure the 330i is faster in top speed and getting there as well.
Still, the 325i seems faster than it's published power numbers suggest. Also, I believe the new 3.0 engine is lighter or weighs as much as the former 2.5 engine.

I think the 3.0 liter in the 325i and 330i makes sense. You have less engines to change the production line thus streamling it for the US run. Going the Nissan model is a good move. Nissan uses that excellent 3.5 V6 in nearly all their cars/trucks yet in various states of tune with either more HP or more torque. They even carry it into the Infiniti line with the G35 coupes and sedans. Great idea.
One great engine, low retooling costs, lower per engine costs, and everyone is happy.

T

I have subsequently see this about the place, and I am not disputing it, but I find it very interesting. Thinking about it intuitively, the Euro 2.5l has the full-meal-deal spec (multi stage intake etc) just like the US 330's 3.0l. To my mind the Euro 2.5 and US full spec 3.0l should theoretically have the same emissions issue, and the 3.0l detuned should in my mind be less efficient.

It appears that this is just one of those strange and counterintuitive aspects of life... BMW's wisdom works in mysterious ways I guess...

As I said, I am not disputing that this is indeed tha case, just noting that it is an interesting situation... Can anyone shed any light on this?