e34 M5's: What's the diff between the

[RockJock]

eurospec 3.6L M5's and the North American 3.6L M5's? Any significant differences other than superficial diffs? TIA.

[Jon K]

I don't think there is any difference. Only a difference in late model 3.8's

[BFEINZIMER]

headlights? cats?

[Brandon J]

Besides the obvious DOT regulations like amber corner light housings and gauges, dash padding design, trim options, etc....there is a slight difference in power and the ecu chip. In Europe, they don't have the same check engine light regulations we do and they also have higher octane gasoline, so there is a few HP extra in the ecu tuning. I have run aftermarket chips tuned for 91 and 93 octane for Euro and US cars. I can run both safely in my US 3.6L.

Here is important info: if you purchase a chip made for europe, your check engine light may not go on if there is something wrong going on.

[Sam-Son]

Besides the obvious DOT regulations like amber corner light housings and gauges, dash padding design, trim options, etc....there is a slight difference in power and the ecu chip. In Europe, they don't have the same check engine light regulations we do and they also have higher octane gasoline, so there is a few HP extra in the ecu tuning. I have run aftermarket chips tuned for 91 and 93 octane for Euro and US cars. I can run both safely in my US 3.6L.

Here is important info: if you purchase a chip made for europe, your check engine light may not go on if there is something wrong going on.
Brandon I'm looking at your sig and the 525 sounds like a hell of acar. Do you have any pics you could post up?

[RockJock]

Thanks guys! I didn't think there were any significant differences either. I was chatting with someone earlier today that told me that there was a difference in the cylinder head. The guy must have been thinking of the 3.8's.

[repenttokyo]

Besides the obvious DOT regulations like amber corner light housings and gauges, dash padding design, trim options, etc....there is a slight difference in power and the ecu chip. In Europe, they don't have the same check engine light regulations we do and they also have higher octane gasoline, so there is a few HP extra in the ecu tuning. I have run aftermarket chips tuned for 91 and 93 octane for Euro and US cars. I can run both safely in my US 3.6L.

Here is important info: if you purchase a chip made for europe, your check engine light may not go on if there is something wrong going on.


can I ask you how much trouble it was to swap the S38 in, and if you would do it again given what you know now?

[whiskychaser]

eurospec 3.6L M5's and the North American 3.6L M5's? Any significant differences other than superficial diffs? TIA.The cost of re-tooling would be enormous so I assume the engines will be the same. From photographic evidence I conclude the only difference is that the N American E34s are shinier. If such a word exists

[RockJock]

---snip---From photographic evidence I conclude the only difference is that the N American E34s are shinier. If such a word exists

why yes, yes it does herr whiskychaser :p

adj. shin·i·er, shin·i·est
1. Radiating light; bright.
2. Bright from reflected light; glistening.
3. Having a sheen from being rubbed or worn smooth.

[whiskychaser]

why yes, yes it does herr whiskychaser :p

adj. shin·i·er, shin·i·est
1. Radiating light; bright.
2. Bright from reflected light; glistening.
3. Having a sheen from being rubbed or worn smooth.
I am impressed. A man with an accurate sense of both genealogy and humour:)

[Jon K]

Europe has the same octane fuel as the US they just go on a "RON" system version our motor octane. 98 there is 93 here. 95 there is 89 here... and so on.

[Brandon J]

That's correct. US e34 M5s were tuned for 91 octane, not 93. I get 93 here in Chicago so I can use the euro version chips based on 93 octane.


Europe has the same octane fuel as the US they just go on a "RON" system version our motor octane. 98 there is 93 here. 95 there is 89 here... and so on.

[ILoveMPower]

From some gurus over at m5board:


At some point in 1990, BMW altered the final drive to 3,73:1 for the HD93 (US) model. Until then, BMW used a final drive with 3,91:1 ratio for all models (HD91, HD92 and HD93). The reason for that was to lower the engine speed under normal driving conditions. The HD91 and HD92 and later the HC91/HJ91 and HC92 models kept the 3,91:1 differential until 4/94 when 1995 model with six speed gearbox came onto the market. I also believe that the HD93 variant has OBD whereas the HD91 and HD92 variants do not. Last but not least, the HD93 variant was manufactured alongside the HC91 and HC92 models during 1992 for the 1993 model year and the last S38B36 engines received some improvements from the S38B38 such as a throttle position sensor in stead of a throttle position switch.


the 92 model year (typically, around 9/91 production) is when bmw NA started getting the 3.73 gearing. 91 model year was 3.91 here.