What fuel?

[Mick_J]

I have two bikes with plastic fuel tanks and both have been affected by the ethanol in petrol.  About 3 years ago I wrote to all the petrol companies in the UK and asked what percentage of ethanol they used, all apart from ESSO claimed at least 5% ethanol in all fuels, including super unleaded.  ESSO said that the regular petrol had 5% but the super has 0% and this will be the case for some time to come.  I confirmed this with ESSO last year and it's still the case.  If petrol stations ae now telling everyone I would suggest it's because they are all going up yo 10% ethanol.  With the exception of the bikes with plastic tanks I use 95 octane in my other bikes.

[KiwiCol]

What does it do to the plastic tank Mick? 

[Mick_J]

What does it do to the plastic tank Mick?

Col

It makes them expand, on my Speed Triple it stretched out wide enough to split the water pump cover, I had to repair the split and then elongate the hole to allow it to refit onto the tank.  On my MZ it expanded lengthwise so that I have to unbolt the tank from both ends rather than just the front and pivot it upwards, it wont clear the handlebars now.  Switching to ESSO super has stopped them from getting any worse.  Ducati had a similar problem and replaced all it's plastic tanks for steel ones a few years ago but Triumph are not interested in it as "it's not a problem we have encountered" as for MZ, they have gone bust so no help is forthcoming from them.

[KiwiCol]

What did Triumph say about your tank?  Surely they've encountered it when you show them yours?  They just pretend it's not happening then?  Are they trying to say it's your fault or something you did to make the tank go like that?

[Mick_J]

Triumph just said there is no evidence that ethanol in petrol affects their tanks and they could supply me with a new one at over £650.  They have stopped making bikes with plastic tanks, as have Ducati (and they admitted it did affect their tanks).  Triumph said they have run tests and it does not affect their tanks but loads of people on the S3 forum say that's shite as it plainly does, and why would other manufacturers fes up if it had no effect.  It only happens to tanks made by Accerbis who used to make all the plastic tanks used on European bikes until ethanol was routinely used.  My BMW has a plastic tank and is fine but is new and not made by Accerbis.

[KiwiCol]

That's pretty crap service from Triumph then.  Sorta puts ya off the brand a bit really.

[ARH]

That's pretty crap service from Triumph then.  Sorta puts ya off the brand a bit really.

Sssshhhhh........ don't tell Barmy 

[Newtons]

Ethanol (aka corn juice) is a cheap way to increase octane rating but has less energy content than straight hydrocarbons, i.e. not alcohols. So you will burn more ethanol blend than non ethanol fuel for the same energy output and get worse economy. This is very pronounced with E85 which is very popular with the ricers and their turbo 4's here in Aus because it allows them to wind up the boost much higher than is possible with 98RON.

I am not across the changes to fuel systems that have been developed to "safely" use ethanol but I'd rather not put ethanol in "older" vehicles because of the potential for damage to rubbers, plastics etc.

The main problem with ethanol is acid production because acid causes corrosion. Ethanol is hygroscopic (absorbs water) and this mixture creates favourable conditions for acetobacter growth. Acetobacter oxidises the ethanol to acetic acid (vinegar smell).

If you can keep water out of your tank and are using the bike regularly, E5 or E10 shouldn't be a problem corrosion wise, but there still remains the issue of rubbers and plastics.

If you are storing your bike I think it's a really bad idea to leave an ethanol blend in the tank.

FWIW I am planning to use 91 with no ethanol with the occasional tank of 98 because of the (marketing dept) reported cleaning properties. But then again injector cleaner additive every few tanks probably does the same job... If you are concerned about pinging/detonation you can load up the engine in too high a gear to see if you can induce it. I've been unable to with 91.

I was actually shocked at the low octane ratings of fuels in the USA. From memory that had 81, 85 and 89RON? I struggled to find even 91 and wondered what people with modern turbo cars that spec 95RON or higher do over there...

[Basil Brush]

Been running on 98 for a couple of years now - no problems. especially laying up in winter as the stuff stays fresh as a daisy all winter...

[Andre]

USA uses MON instead of RON which is about 8-12 octane lower. The 89 MON is about the same as 98 RON

Just found out that there is another problem with ethanol: it has another stoichiometric AFR than pure petrol. E10 (only the one that really contains 10% ethanol) is 14.04:1 while pure petrol is 14.7:1 (sorry, don't have the E5 number and to lazy to figure it out). Pure ethanol is 9:1 btw.

You can't be sure how much ethanol is in the ethanol/petrol blends. If you have a lambda sensor, the ECU makes the adjustments automatically (to a certain degree). We don't have these on the 14 (exception PC with Autotune). The only way to be sure that your AFR is were it should be is to use pure petrol.

[Newtons]

Been running on 98 for a couple of years now - no problems. especially laying up in winter as the stuff stays fresh as a daisy all winter...

Probably the best option. All you have to lose is the difference in cost. 98RON where I am is quite a bit more expensive than 91. Around 20c/litre I think so if neither have ethanol and you don't need the knock control then there really is no point paying the extra for 98 aside from the speculative cleaning properties. Speculative because there does not seem to be any factual evidence rather than marketing gumph available to support these cleaning properties. :shrug:

[Newtons]

USA uses MON instead of RON which is about 8-12 octane lower. The 89 MON is about the same as 98 RON

Just found out that there is another problem with ethanol: it has another stoichiometric AFR than pure petrol. E10 (only the one that really contains 10% ethanol) is 14.04:1 while pure petrol is 14.7:1 (sorry, don't have the E5 number and to lazy to figure it out).

You can't be sure how much ethanol is in the ethanol/petrol blends. If you have a lambda sensor, the ECU makes the adjustments automatically. We don't have these on the 14 (exception PC with Autotune). The only way to be sure that your AFR is were it should be is to use pure petrol.

Ah, thanks for the RON/MON distinction - didn't know that.

I doubt E5 or E10 would significantly impact the AFR but def another reason to stay away from ethanol blends. The turbo kiddies I mentioned use a "flex fuel" sensor to detect the % of ethanol and feed that into the ECU. Obviously E85 would have a significant effect on AFR if not compensated for.

[SheepDog]

I'm no expert ...

I spent alot of time driving for work and tried all types of brands and RON levels (had that great fuel card and work car). Some days one brand and its RON 91-95-98 worked well, with the car smooth and responsive and quite. Other days not so smooth etc. Maybe the gods, maybe the planets aren't aligned.

The 1400 I must say is happiest with Mobile Special Unleaded - 91. I tried their 95 but the Special works a treat, good economy. It just feels good riding, responsive, accelerating, you know. Tried Caltex and BP but still go back to Mobil (not a fan of Shell).

Anyway .... just my input.

[Andre]

The 14 is adjusted from factory for RON 91. Unless you made certain changes to the engine, higher octane isn't needed.