Talk Morgan Forums Morgan Sports Cars Classic Morgans (pre-CX) Monty MPG Test

Off to see old friends today, we needed to felttle and exercise the Talbot.

[url=https://ibb.co/y6s3snq]

So I figured I'd do a little 132 mile MPG test of the fully tuned Monty.

I'd completed the same test with Monty, over the same route, and under the same driving conditions in his standard completely untuned 143 horsepower spec, so I thought it would be interesting to see how much more fuel Monty was consuming now in theory he's making around 200 horsepower.



Here's the results:

Pre Tune = 37.6

Post tune = 37.2

These were both brim to brim tests over the same roads using the same fuel station, both were 68 miles of motorway (M25 &M11) at between 75-85 mph, and a further 64 miles of evenly mixed A & B roads at an average speed of 51 mph. So, overall good mixed driving conditions, although admittedly no town driving and very few of what I would describe as enthusiastic acceleration events.

To be honest a difference of 0.4mpg is so small you could easily attribute it to the inevitable variables such as traffic and the differences in climatic conditions between the two tests, I conclude that if driven in the exact same way the now much faster Monty is actually no more or less economical than an absolutely standard un-tuned Duratec Plus 4.

Happy with that

I should also say I've always run Monty on E10, and it's important to understand E10 has a lower calorific value by volume than E5, so there is potential scope to improve my 37.2 simply by switching to E5. However, we need to separate fuel consumption, which is how much fuel the engine consumes over a fixed distance, from fuel economy, which is how much it costs to cover that same fixed distance.

E5, or what is being marketed at the pump these days as 'Super Unleaded', is of course more expensive to buy, so the real question we should be asking ourselves is....

Is running E5 'Super Unleaded' really worth it

In terms of ethanol content the new 'Super Unleaded' (E5) is actually more or less identical to the old 'Regular' we used to get at the pumps before September 2021, however, it does retain the higher 98 Ron octane level of the old 'Super Unleaded'. Make no mistake, this means even the new 'Super Unleaded' has a lower calorific value than the 'Super Unleaded' we were buying just two years ago. So, even if you've always run 'Super Unleaded', your fuel consumption will have increased in the last two years, and you can do nothing about that!

When E10 became the standard grade of petrol in September 2021 the AA said that fuel consumption would rise by about 1.6%, the UK government agreed with the AA when they quoted a 1-2% increase. We must consider this before we get sucked into all the millions oil companies invest in trying to encourage us to pay the 2-3% premium they typically charge for their so-called 'Super Unleaded'.

Also keep in mind that you will only see an additional benefit from the slightly higher octane level of 'Super Unleaded' if you or your ECU can advance your ignition timing to make use of it's greater resistance to knock (detonation), and even then you'll only really see a tiny power benefit under acceleration/load. E10 is still 95 Ron whereas E5 is typically 98 Ron, but in terms of consumption you'll be lucky to achieve any more than a 0.5% reduction in how much fuel the engine consumes from the slightly higher octane element.

Clearly paying a 2.5% premium or more for 'Super Unleaded', that at the very best will actually only deliver a 2% improvement in fuel consumption is a false economy, so if your car can accept E10 there's seldom any logical reason (other than a feel good factor) why you should ever choose 'Super Unleaded' over the cheaper E10 fuel.

However, if you run an older car that can only accept E5, you must pay the premium and use 'Super Unleaded'!

In summary, just like ULEZ, the move to E10 is actually another Tax on the poor who can't afford to buy a newer E10 compatible vehicle, the environmental sales pitch from the Government is really just a classic smoke screen (no pun intended). Just like ULEZ and air quality, the evidence presented to try and persuade us that E10 helps to meaningfully reduce carbon emissions is very weak indeed. When you study the facts, it's far more likely what we are actually seeing here is a Government strategy to stimulate new car sales. This is good for the economy, Tax revenue and the rich who invest in car production to enjoy dividends from the industry, but bad for the environment because it takes a massive amount of carbon to build a new car, especially an EV.

What we should be doing is encouraging people to keep their older cars longer, because while the older car will have higher tailpipe emissions the additional carbon it produces is still massively lower than the carbon it takes to build a whole new car to replace it. Instead of spending tens of millions on ULEZ cameras and pushing low energy ethanol on us, the money should go towards grants that pay for retro-fit modern engine management systems and high efficiency catalytic converters on older vehicles.

Such a strategy would support current thinking that says to repair and improve what you already have is a way more environmentally sound approach than making something new to replace it, only to throw what you already had that was actually perfectly serviceable into landfill.

Fully agree though the E5 I buy currently is Esso and that has zero ethanol though that is changing.

Sadly John, that's all about to end

Esso have announced from next month their premium fuel known as 'Synergy Supreme' will contain 5% ethanol.

Open up 'How much ethanol is in Esso's E5 fuel?' in the following link to he Esso website.

https://www.esso.co.uk/en-gb/faqs



So, you may as well switch to E10.

I found my MPG improved with E10

Mine does too, making it almost cheaper to run on E5.

The calorific value of ethanol (E100) is 29.78 MJ/kg, if you put 10% of the stuff in petrol (E10) the calorific value of the fuel will be decreased from 44.40 to 44.22 MJ/kg, so the difference is tiny.

This is supported by the VTT Technical Research Centre of Finland, they measured fuel consumption under normal driving conditions and their study showed there is practically no difference between commercial petrol grades 95E10 and 98E5.

As I've said already, if you car is E10 compatable, you may as well use E10.

That is very interesting Montegue, thanks for posting.

I have done my first mpg on the new Plus Four. 45mpg on E10. Next test will be on E5
A few years ago I commuted 60 miles each way,West Wales to Cardiff using M4. Car was a Focus turbo diesel. Out of curiosity I tried Millers Octane boost with standard diesel. A bottle cost £12 and was used to dose a few tanks. Over the volume of the bottle I saved £37 gross so £25 net on diesel by increased mpg. A colleague tried it in his Golf diesel but no benefit. Probably differences in the ecu map or his driving!
In the Plus8 I was getting occasional MIL lighting up. Fault was”random intermittent misfire”. The Gems picked it up and the stats package triggered the light when the trigger point was reached. Checked as much as I could but the solution to stop it was use Shell V-Power. 97octane zero ethanol. If I still had the car I’d give Millers a try with 95 octane E10. With the V-Power I got 1-2 extra mpg and felt the engine ran smoother but a marginal thing only.

There was a reasonably competent test done of the various 'sporty' petrols and the only one that gave a detectable increase in bhp was V-power ... that's why it's almost universally used by motorsport competitors in disciplines restricted to 'pump fuel' (and who can't afford the seriously expensive drums of specially mixed 'pump fuel' that has the constituents closely tweaked to meet the regs but give best results on the dyno ...a sort of 'designer' pump fuel)

Also it's best bought from a busy petrol station where the turnover assures regular deliveries as the 'good stuff' goes off in storage.

K