Author Topic: Super unleaded vs standard unleaded  (Read 9697 times)

Offline Sootchucker

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Super unleaded vs standard unleaded
« on: 09 March 2022, 11:10 »
Hi guys, I know there have been tons of threads on this in the past, so pease excuse me. I have run the GTI since day one on super unleaded 99 Ron (mainly Tesco Momentum). However with fuel prices rocketing lately, and there being a good 7p per liter between both, I've started wondering if it's worth changing to standard 95 Ron.
I know the car will run on it, but with the 95 Ron being an E10 mix I'm wondering if the worse MPG from using 95 Ron, balances itself from the higher costs of 99 ron (approx £3.15 extra per tank) ?

Thoughts please ?
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Offline willni

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Re: Super unleaded vs standard unleaded
« Reply #1 on: 09 March 2022, 11:58 »
Hi guys, I know there have been tons of threads on this in the past, so pease excuse me. I have run the GTI since day one on super unleaded 99 Ron (mainly Tesco Momentum). However with fuel prices rocketing lately, and there being a good 7p per liter between both, I've started wondering if it's worth changing to standard 95 Ron.
I know the car will run on it, but with the 95 Ron being an E10 mix I'm wondering if the worse MPG from using 95 Ron, balances itself from the higher costs of 99 ron (approx £3.15 extra per tank) ?

Thoughts please ?

I'd run 4-6 tanks of E10 and see how the real mileage changes for you between now and the last tank of E10, you can analysis percentages and mpg's but real world will be difference.

Also I filled up with 97 Ron last week while E10 fuel was £1.54 my E5 was £1.57, the E5 rose 3p a litre and the E10 rose 5p.


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Offline ub7rm

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Re: Super unleaded vs standard unleaded
« Reply #2 on: 09 March 2022, 11:59 »
I think you would have nothing to lose to see what happens as an experiment.  You would probably need to run a couple of tanks through to let the car adjust properly to the new RON rating and get 'steady state' data to compare.
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Offline dubber36

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Re: Super unleaded vs standard unleaded
« Reply #3 on: 09 March 2022, 13:18 »
Different car I know, but we have a 2013 Polo 1.0TSI for everyday driving around. I mistakenly filled it with super the other week. It had done 420 miles on the previous tank, with a range of 20 miles left. I wondered if the super would give better economy, so said nothing to my wife in case it influenced here driving style. Once the tank of super had got down to 25 miles to go, it had done the grand total of 410 miles. Not conclusive proof, and I know others say it needs 3 or 4 fills of super before you see any difference, but I will be more careful which pump I pick up from now on.
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Offline Exonian

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Re: Super unleaded vs standard unleaded
« Reply #4 on: 09 March 2022, 18:14 »
When faced with the shattering worry of having to save approx the cost of one pretentious paper cup coffee per tankful over the cost of a higher octane fuel there are probably a few things to consider.

Firstly, is my car tuned for SUL or does the fuel cap just recommend 95 anyway?

Am I on minimum wage struggling to feed and heat the family, or did I spend tens of thousands on a car then heap a load of extras into the mix and only use the highest quality maintenance and cleaning products?

What will I actually do with that £3.50 I saved and why was I putting 99 in it anyway when the cap recommended 95?

Will I do enough miles a year to actually gain more than about £50 by switching fuels and therefore how do I find the link to the forum charity to spread my newfound wealth?

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Offline mb

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Re: Super unleaded vs standard unleaded
« Reply #5 on: 09 March 2022, 22:06 »
I got my Mk7.5 in December 2020 and since then I've only put one tank of Super Unleaded in it. Regularly get 370-390 miles from a tank of normal unleaded.

Only used Super a handful of times in my Mk7 in the six years I owned it.

Used it about every fifth tankful when I had a Mk5.

Offline JMS

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Re: Super unleaded vs standard unleaded
« Reply #6 on: 09 March 2022, 22:45 »
Exonian nailed it.

Great answer.

However if you really are that hard up but don’t want to neglect your p&j, Esso E10 fuel actually has very little ethanol in it. The E10 rating means up to 10%
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Offline Exonian

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Re: Super unleaded vs standard unleaded
« Reply #7 on: 10 March 2022, 05:58 »
All meant in jest as I’ve known Sootchucker on the forums since at least the mk5 days when he had a black(?) GT TDI with a really nice spec, and he’s a really nice guy who looks after his cars with utmost pride.

Well, not all in jest as the forum charity was a serious bit and the underlying message was from the heart.

That’s a really interesting fact about the Esso fuel having much less E10 in JMS, and one well worth bearing in mind.

Something I missed off my last post due to time constraints was to add in about driving style making a difference too, not just to outright economy in either direction, but also as to whether you’d see any benefit at all in a GTI tuned for 95 RON in running 98/99 if the car was generally driven at low revs and using moderate throttle.
Combine an economical driving style (brisk but not using high revs) with lower octane fuel, use anticipation and light braking, then all together you’d see a reasonable saving (or levelling off more accurately) at the pumps as fuel costs rise ever upwards.

Last week I put in 35 ish litres at 156.9p per litre and last night 40 ish litres went it at 162.9p, in normal times that would bother me but to be honest I’ve been glued to newsfeeds 24/7 in disbelief/horror/anger at events unfolding hour by hour like many others here I’ll assume. We’ve just got to be grateful for our own small mercies right now.
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Offline Adam T7

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Re: Super unleaded vs standard unleaded
« Reply #8 on: 10 March 2022, 06:43 »
Totally agree. I do so few miles now that I will continue to fill up with Shell V-Power E5 99 RON and give the price a cursory glance and sigh. Tank lasts me over a month.
If I was doing the near 20K pa mileage of about 6 years ago, I’d probably have a different view.
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Offline Watts

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Re: Super unleaded vs standard unleaded
« Reply #9 on: 10 March 2022, 08:57 »
Getting out in the car is great particularly as my OH is suffering from some mental health issues at the moment which can make being in the house rather traumatic most days. She always feels better when we go somewhere so we get out a lot right now so a few quid extra on a tank is not an issue.

As to the original question, there is about a 3% decrease in economy with E10 and a negligible improvement with SU. So I would estimate you are going to lose around 1 mpg or 11 miles per 11g tank which at an average of 35mpg means a range drop from 385 to 374 miles. So assuming fuel prices of £1.55/£1.62 per litre, that means £77.50/£81 per tank. On the two fuels then you are getting 4.83/4.75 miles per £1. So not really all that much in it and presumably there is a good reason why you have been using SU from day one? That won't have changed and you've been happy spending the difference so far so I'd say carry on.
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