CAUTION E10 fuel

[pologti18t]

my remapped 1.8tsi absolutely loves 100RONe10. Power & torque go up, fuel economy is worse but that's the trade off for a lower calorific value compared to a higher octane. I just wish it was more readily available near where I live.

I've had the same experience in my APR'd 1.8T GTI. Loves the stuff... especially in the mountains.

[brad]

I've also thrown half a tank of E85 into half a tank of 98. It gives you about 105ron IIRC. The engine loves it but the economy is about 30% worse (to be expected) & I haven't checked at which point the injectors go into 100% duty cycle.

[wai]

I've also thrown half a tank of E85 into half a tank of 98. It gives you about 105ron IIRC. The engine loves it but the economy is about 30% worse (to be expected) & I haven't checked at which point the injectors go into 100% duty cycle.

Not a good idea. Unless you have tuned it for this (and not just the RON), you can end up with a holed piston or burned exhaust valve. Normally the ECU will not be able to make sufficient adjustments to the injection and timing to cope with such a different fuel:air+oxygen mix.

[brad]

The increased Octane won't have a negative effect.

Certainly the ethanol will give a leaner mixture but it also burns cooler. One of the reasons the fuel consumption increases is not just because of the reduced calorific value of the ethanol but because it runs lean, so the ECU ups the flow to the injectors to compensate.

As i said, you need to check at which point the injectors are reaching 100% of the duty cycle.

[Diesel_vert]

Officially, Volkswagen have approved the use of ethanol blends of up to 10% in all vehicles (except for certain engines, none of which were imported here).

Vehicles with "MultiFuel" technology are designed to use ethanol blends of up to 85% (these vehicles are not imported here).

Vehicles that require 95 RON must use premium unleaded (95 RON) or premium unleaded E10 (97~98 RON) or higher.

Only vehicles that can satisfactorily run on regular unleaded (91 RON) may use regular unleaded E10 (93~94 RON) or higher.

Recently put some RON 98 / ethanol 10% blend into my poor 77TSTI.
Do not use this fuel type whether 95 or 98 RON.
Fuel consumption up by at least 10%
Power down by a similar amount
Lesson learnt

On a technical level, I consider regular unleaded E10 (93~94 RON) as an alternative to regular unleaded (91 RON).

Likewise, I consider premium unleaded E10 (97~98 RON) as an alternative to premium unleaded (95 RON).

As I do super unleaded E10 (100~101 RON) to super unleaded (98 RON).

This is because the ethanol component in petrol does not give an appreciable increase for MON (motor octane number) like it does for RON.

I thought 98 was the minimum to use across the whole Polo range

All Volkswagen vehicles will satisfactorily run on 95 RON.

However, some vehicles will need 98 RON for maximum power.

Remember though that Australian petrol is pretty crap compared to the European stuff so I wouldn't be surprised if our 98 was on the same level as their 95...

No. RON is RON all over the world (even if Australian regulations allow more sulphur in petrol than European regulations).

Im not sure about Europe but USA use MON instead of RON as the measurement. 98 RON is equivalent to 93 MON I think. 87 is their standard, our 91.

In the US, petrol pumps are labelled according to its AKI (anti-knock index), which is calculated using the average of RON and MON, i.e. (RON+MON)/2.

87 AKI = 91 RON
91 AKI = 95 RON
93 AKI = 98 RON

Also with the mk7 TSI I will say that I'm not sure if it can run ethanol

Volkswagen have approved ethanol blends (E10 or E85, depending on the engine) for the Golf Mk7.

BUT what I'm thinking is that because every VW is now turbocharged (for the most part, you know what I mean) and the min requirement is 95 for all turbo engines I think the dealer would expect that your only going to put in premium 95 ron - in which none of the petrol operators run 95 ron ethanol blends. I understand they make 98 ron ethanol blends but I guess it just complicates things.

I guess you could run 98 blend because its 95 with a boost from the ethanol

Yes. In the same way that adding 10% ethanol to regular unleaded (91 RON) yields a 2~3 increase in RON, adding 10% ethanol to premium unleaded (95 RON) also yields a 2~3 increase in RON.

but 91 blend is 87 ron with a ethanol boost...

No. Regular unleaded E10 will always have a RON of at least 91 (i.e. the petrol component).

Just to add my two cents to this, I once ran my V-twin ride-on mower on E10 for about three months and it stuffed up the carby and some other seals and it still doesn't run as well as it did before that, even though I've been running normal unleaded in it for a year since.

Not all engines are compatible with ethanol blends. Always check with the manufacturer.

it clearly states in the owners manual (yeah, that thing that lives under the flap in the glovebox that has a whole lot of information on how your car works) to not put any ethanol blended or bio-diesel blended fuels into the polo range of engines.

Are you sure? That seems inconsistent with Volkswagen's position on ethanol blended fuels, especially E10 blends.

[gavs]

Positive because as an alternative fuel supporter, I was hoping to run the GTI dedicated 100RON with the E10 blend and was disappointed when the manual says not to.