Best Fuel For Your Is

[Fidgits]

After running my IS on 'normal' unleaded for 18 months, I was advised that the IS ECU can adjust to the higher RON rating on Super Unleaded, and in essence, provide better performance, for the same price.

So I performed a test over the last 2 months.

The test route was 180 Mile round trip. 90% of this route was on a Motorway, with the remaining being stop/start town driving.

Each test run was performed either early morning, or late night, where traffic was at a minimum.

The driving was at the speed limit, with 'normal' driving style (not heavy footed, or overly ecomonical).

I allowed 2 full tanks of the new fuel to be run through the engine before taking the results (to allow the ECU to adjust).

For the first month, I fuelled with Super Unleaded (from Esso), I noticed an improvement in acceleration, the car requiring less throttle to accelerate up to motorway speed. The engine was more responsive. The relative cost of fuel was almost identical to normal unleaded.

For the second month, I fuelled with Shell Optimax, there was an improvement in responsiveness over the 'standard super unleaded', and the car seemed to have better 'mid-range pull'.

The cost of fuel seemed to be actually less for this journey, and saved me around 1 to 2 pounds for the 180 mile round trip.

The Cost of each fuel (all figures approx)

Normal Unleaded fuel (95 RON): @76.9 = 12.7p/mile

Esso Super Unleaded (97 RON): @79.9 = 12.9p/mile

Shell Optimax Super Unleaded (98 RON): @79.9 = 11.6p/mile

The above figures were worked out as the average of 2 of the journeys, but from this test, it seems if you use Shell Optimax in your IS, you can get better performance, and a lower cost.

[altezzaz]

This is a bit of an eye opener, but there is a LOT to read....

Octane Boost thread

[Monster-Mat]

That MYCROFT gets everywhere, and is ultimately banned from everywhere.........

take from that what you will, he is known to copy / paste other peoples info to make himself look good.........

ask about him on the supra forums, and quite a few others aswell......

[ekky]

I can back up Fidgits cost per mile using Optimax,

I've got 11.7p per mile based on 365 gallon Optimax used over the last 8 months (Journeys normal 27 miles, 20 on motorways the rest city centre).

Fuel economy normally around 29 to 30 mpg, but i did manage 35 mpg on a long run

[ColinBarber]

Where do people get their optimax from? I have never seen it under 80p. It's normally 82 or 83p where I live, 6p more than Shell unleaded.

[whitie]

Portsmouth area about 78p

[ekky]

up until about a month ago I was paying 76.9 per litre for Optimax, but over the past month it gone to 80.9p per litre.

The garage is on the A41 in Birkenhead its always cheaper than other places but the refinery is only just down the road

[Damer]

In the past month or so I have been using Optimax and noticed getting about 50-60 miles more to the tank over standard fuel. However in the middle of that I used BP's premium fuel (forgot what it is) and got nearly 80 miles more and that definately "felt" better, but may just have been ECU kicking in.

[Wosket]

i also noticed an increase of an extra 50-60 miles per tank with optimax but only when i was travelling around a fair bit. normal town driving and it didnt last any longer, so i switched back to normal unleaded as i mainly drive around manchester. i did notice the car was a tad more responsive with optimax but nothing to really write home about.

[Parthiban]

i agree with that, around town doesnt seem to do much so will probably go back to normal unleaded soon, however, will miss the better performance

[kev dood]

over a whole tank of fuel, optimax saves me about £1-2. Its "miles" better!!

Colin, where abouts in Surrey are you? There is a Shell garage near Addington Palace which is sort of Addington which is about one of the cheapest near my parents.

I must admit, not all Shells optimax's are up to standard, there is one garage near me that has given me 2 tanks of rubbish so I never go to that.

[altezzaz]

Anybody got any comments on Total, Elf or Fina super? - I can't understand the comment in the thread that it has a higher calorific value but a lower octane rating than Optimax.

[TonyGoose]

can't understand the comment in the thread that it has a higher calorific value but a lower octane rating than Optimax.

Does that mean it's more fattening ?? :shutit:

[Wosket]

can't understand the comment in the thread that it has a higher calorific value but a lower octane rating than Optimax.

Does that mean it's more fattening ?? :shutit:

[mattstheone]

i put around £46.00 in my Is200 sport and get an average 380 mile

is this the norm,

or should i change to Optimax or somthing similar to get more MPG

i am travelling on the motoway to and from work each day around 46 miles

Bit off record but as we are talking petrol i have noticed that you have to hold the nozzle at a strange angle or the auto cutoff keeps happening on the pumps dont matter what garage i go to

can i remove that white plastic part in the fuel filler neck

or will it cause a problem

[squarehead]

i have noticed that you have to hold the nozzle at a strange angle or the auto cutoff keeps happening on the pumps dont matter what garage i go to

I kind of agree with mattstheone on this one. I seem to have the same problem at Tesco time & time again. As I do a lot of travelling it is not just my local Tesco I have noticed it in Northampton as well!!!

I got so fed up with it one day and complained about it to them and they said it was a fault in the pump and they could do nothing about it. I have also filled up in Sainsbury's and didn't have a single problem.

Slightly off-topic I live inbetween Chester & Wrexham and the petrol prices here are really good compared to say Nothampton & Essex for example. Even Optimax is cheaper in Wrexham than standard unleaded in Essex.