Using E5 Fuel on the iQ

[Barkley]

This isn't meant to sound smug - but I'm now approaching 70mpg on the iQ2 which I find incredible.  Since I purchased it last year, I decided (because of its age) to restrict it to E5 instead of the more standard E10 Unleaded - primarily because the iQ was never designed for it and it was introduced for more modern cars.  I resolved that since my Road Tax was £0.00, I'd treat it to Premium fuel (E5) wherever I could.  Apart from one fill of E10  in Aintree, it has had 7 fills of E5 everywhere else.  Now, for the first month my mpg was 53.61-55.40, but this has steadily been climbing so whilst my driving over the last 8 months hasn't improved, the fuel has given me a 15 mile boost per gallon to 69.85.  Perhaps (like EV's) the weather may play a part, but wondering what others have found?

[Cyker]

Warm weather always seems to help, although it tends to affect EVs, hybrids and diesels more than petrols. Partly because tyres tend to heat up faster and run at higher pressures, but also the engine doesn't have to waste as much energy keeping itself warm, so more goes into moving the piston instead of heating up the cylinder block.

Might also be the car's fuel system has had a good clean from all the super-unleaded usage, although usually I find that usually provides a noticeably improvement and each subsequent use the improvement is smaller and smaller.

[Mojo1010]

More to do with the warm weather than fuel grade for that different in mpg. 

[Jikky]

23 hours ago, Barkley said:

This isn't meant to sound smug - but I'm now approaching 70mpg on the iQ2 which I find incredible.  Since I purchased it last year, I decided (because of its age) to restrict it to E5 instead of the more standard E10 Unleaded - primarily because the iQ was never designed for it and it was introduced for more modern cars.  I resolved that since my Road Tax was £0.00, I'd treat it to Premium fuel (E5) wherever I could.  Apart from one fill of E10  in Aintree, it has had 7 fills of E5 everywhere else.  Now, for the first month my mpg was 53.61-55.40, but this has steadily been climbing so whilst my driving over the last 8 months hasn't improved, the fuel has given me a 15 mile boost per gallon to 69.85.  Perhaps (like EV's) the weather may play a part, but wondering what others have found?

Ive been using e5 for about 8 months in my iq3 now, and have noticed im getting considerably more mpg ,I do a 260mile run from london to pembrokeshire 4-5 times a year returning with only one bar on my fuel guage,per tank,but using e5 im coming back with 2-3 bars...

[fasda]

I've had my 1.3 with 18" alloys for almost 4 years. Every fill up with Tesco Momentum 99, i never get less than 54mpg. The only time i had to use E10 (low fuel in tank and no 99 available), i got 47mpg. 

[Barkley]

22 hours ago, fasda said:

i never get less than 54mpg.

Certainly the 1.3 is a little more thirsty than the 1.0, but I'm glad others are seeing similar benefits - the acid test will be in the next 3 months as that will be a complete year and I can better gauge the 12-month cycle. With my previous EV I was certainly used to collapsing Battery capacity affecting range, but I'm really only doing short trips which usually hammers MPG!  Time will tell, and I'll add my findings to the thread later. Tks for your input!

[Dutchrav]

My IQ runs about 50MPG on E0 fuel (BP Ultimate, no ethanol) and just today i noticed still a full display for the fuel.. after 140miles... display said average of 50MPG. In my thoughts the fuel bar should be already lower.

For few minutes i thought something was wrong.. broken fuel sender, faulty display?? 
Just then, the upper fuel digit goes off.

Amazing.. 

[FROSTYBALLS]

On 7/31/2024 at 3:55 PM, Barkley said:

Since I purchased it last year, I decided (because of its age) to restrict it to E5 instead of the more standard E10 Unleaded - primarily because the iQ was never designed for it and it was introduced for more modern cars.

The Daihatsu designed Toyota KR series of engines were introduced in 2004 in the Daihatsu Boon (also sold as the Daihatsu Sirion (Europe), Toyota Passo, Subaru Justy and produced by Perodua as the Myvi), and in the Aygo (2005), Yaris (2006), IQ (2008) in Europe.

Since 2011 cars sold in the EU had to be compatible with E10.

When E10 was introduced into the UK, Toyota stated that "E10 petrol is cleared for use in all Toyota European petrol models made from January 1998, excluding: Avensis 2.0 litre with engine 1AZ-FSE made between July 2000 and October 2008. Avensis 2.4 litre with engine 2AZ-FSE made between June 2003 and October 2008."

As the KR has always been compatible with E10, it must have been designed as such.

[TonyHSD]

E5 is so much better fuel then E10. Not just the mpg but overall performance and drivability are greater on petrol with smaller amount of ethanol and higher octane numbers. And these benefits apply to all cars not only to supercharged, turbo charged high power engines.
In fact  the more efficient and the smaller is the engine more sensitive to fuel is., it’s exactly opposite to what the masses speaks about and the general perception. 

[Dutchrav]

Agree the IQ is compatible with E10, same as our 2017 and 2019 Toyota hybrids.

All our ´metal kids´ deserve only the best.. so they get the ethanol free fuel.
They are happy with it, my feel and mind is same and that is worth every exta penny.

[Pete.Z]

E10 works just fine for me, and it is so much cheaper that I don’t seebthe benefits of using E5, I will not make that difference back.

Engine is designed for E10 anyway, so no harm done.

[Barkley]

On 8/4/2024 at 1:51 PM, FROSTYBALLS said:

As the KR has always been compatible with E10, it must have been designed as such.

Thanks for the clarification - after the year is up, I’m going to try E10, but mentally I do like the reduced Ethanol!