E10 Petrol

UK forum for general and technical discussion about the Z3 roadster
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Richi
Joined: Fri 01 Jun, 2007 15:46
Posts: 60

  Z3 roadster 2.8
Location: York

E10 Petrol

Post by Richi »

From next week, the new E10 petrol with 20% ethanol will be on the forecourts. The gov.uk website says all BMWs regardless of age are compatible?

https://check-vehicle-compatibility-e10 ... ce.gov.uk/

Any views ?
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Robert T
Site Admin
Joined: Mon 12 Jun, 2006 10:35
Posts: 10134

  Z3 roadster 1.9
Location: Cheshire

Re: E10 Petrol

Post by Robert T »

E10 petrol contains 10% ethanol (the clue is in the name). It shouldn't cause any problems for fuel injected cars like ours. The main issues are degradation of rubber fuel hose, which I'm pretty sure we don't have, and the formation of ethanoic acid as ethanol is hygroscopic. The latter is an issue on classic cars with fuel sitting in the float bowls of aluminium carburettors. Other than that, the ethanol increases the octane rating of the fuel and reduces the cyclic variability of combustion resulting in smoother running.

So whilst I'm not worried about using it in either my zed or the Sprite, it won't actually affect me as I run both cars on V-Power, which is staying as E5.

Cheers R.

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Arctic Silver '99 Z3 1.9 & Black '59 Frogeye 1275cc
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LaRy
Joined: Mon 12 Nov, 2018 17:47
Posts: 98

  Z3 roadster 2.8

Re: E10 Petrol

Post by LaRy »

I agree with everything you say, Robert T. I'm even driving my Z3 with V-Power or equal, and will continue to do that. Maybe it is ok for the engine, but all the rubber fuel hoses we have. The vent system for the tank! If those start to leak, it will take many hours to get the tank out to change those.
I'm also thinking of the engine problems Z3 had in the beginning only in the US, caused by poor petrol. That is why I will continue to use 98 octane. I don't take the risk for the few miles i drive during the summer.

An example, the manufacturer does not know everything. Look at the cylinder head cover gasket. When produced, BMW did not know that the new syntetic oils destroyed the rubber, now causing leaking gasket. The rubber becomes very hard.
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Robert T
Site Admin
Joined: Mon 12 Jun, 2006 10:35
Posts: 10134

  Z3 roadster 1.9
Location: Cheshire

Re: E10 Petrol

Post by Robert T »

Rubber fuel hose may or may not be a problem. The stuff I had on the Sprite didn't like E5 and went brittle and cracked in the engine bay. I have replaced it with some from a company that does race car parts and it is lasting way way better - it is a different compound with reinforcing layer. So it really depends what is actually on the car, but if it were an issue it is likely to already have shown up with E5, so I am not overly worried.

Cheers R.

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Arctic Silver '99 Z3 1.9 & Black '59 Frogeye 1275cc
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