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"Normal" petrol in the Evora


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Last Thursday the petrol light came on in the Evora. I went to fill up as usual, but it seems the four horsemen of the apocalypse have emptied the local petrol stations.

It's my daily driver, and peddling around on my bike is getting old fast.

My question is, what happens if I fill up with normal petrol? I always used BP Ultimate, but I reckon I've got more chance of waking up next to Rachel Riley than finding some of the high octane stuff.

 

 

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Nothing much in the short term. Longer term the engine may adapt to the lower octane and adjust the boost pressure to accommodate the higher instance of detonation. This only really affects forced induction cars too, higher octane is of no use to naturally aspirated cars and makes no difference.

Rachel says hi too :D

 

88 Esprit NA, 89 Esprit Turbo SE, Evora, Evora S, Evora IPS, Evora S IPS, Evora S IPS SR, Evora 400, Elise S1, Elise S1 111s, Evora GT410 Sport

Evora NA

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Just setting off to my lotus garage for a service and Mot 🤞🏻
when I checked last night with dealership that all their staff were in and if any garages had fuel (200 miles left) they said it’s pot luck 

during conversation spoke about getting any type of fuel into car and in short term switching not issue but long term best to stick to one type so ECU can learn ! 
now that end of my ability to understand so I am going to try and stick with this new E10 and bask in notion of dolphins and butterflies are breathing easy 🤫

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Just had my car sorted MOT was fine just a tiny advisory about slight fraying on handbrake cable 

otherwise had new brake switch so no more traction light coming on , going to miss it been a constant companion ! Lol 

car felt a little lumpy after filling up with E10 this morning but lotus mechanic told me to persevere with it and should settle down after a few weeks 

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You should come up here to Tayside, no shortages, no issues and no [email protected] panic buying.  

Edited by Bravo73
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Alcohol. Sex. Tobacco. Drugs. Chocolate.  Meh! NOTHING in this world is as addictive as an Evora +0. It's not for babies!    

The first guy to ride a bull for fun, was a true hero. The second man to follow him was truly nuts!   

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14 hours ago, Bibs said:

Nothing much in the short term. Longer term the engine may adapt to the lower octane and adjust the boost pressure to accommodate the higher instance of detonation. This only really affects forced induction cars too, higher octane is of no use to naturally aspirated cars and makes no difference.

Rachel says hi too :D

 

It's about compression ratios in NA cars. A fancy modern motor with a huge specific output would retard ignition and lose power if you use normal fuel. Fortunately, the Evora doesn't have a swanky engine designed for maximum power so you can put anything available in it and you'll be fine.

My main point being it's not only for FI cars.

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Are there any production cars with variable compression ratios? Octane rating is resistance to detonation, nothing more and the more charge you force into an engine the more likely it is to detonate prematurely, pretty much what FI cars can do and NA cars don't as they work to fuel maps based on fixed compression. 

That's what Rachel told me anyway :)

88 Esprit NA, 89 Esprit Turbo SE, Evora, Evora S, Evora IPS, Evora S IPS, Evora S IPS SR, Evora 400, Elise S1, Elise S1 111s, Evora GT410 Sport

Evora NA

For forum issues, please contact the Moderators. I will aim to respond to emails/PM's Mon-Fri 9-6 GMT. 

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Lower octane fuel will reduce performance. The engine is modified by Lotus to give more power by using the octane level recommended. The modifications will have included compression ratio, valve timing and lift, as well as spark timing. To avoid flame front detonation Lotus also use over-fuelling to quench the flame front - all standard practice in performance engines. The lower octane fuel may operate safely but there will be a performance hit as well as a lower mpg (the engine will be running less efficiently). Whether it will be noticeable on the road is another question. At what point the ecu learns and keeps the reduced settings and then needs to be reset when you go back to higher octane fuel, only Lotus knows.

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@C8RKH The [email protected] in Scotland panic buy in a more orderly fashion?

The Petrol Retailers Association, which represents 5,500 independent forecourts across the UK, said about a quarter of the garages it had surveyed in Scotland on Tuesday morning were completely out of fuel.

A further 35% were out of either petrol or diesel, while the remaining 40% had supplies of both.

On Wednesday it found the number of dry sites in Scotland had reduced to 15% while the UK figure was 27%.

The association said the issue was not as severe in Scotland as in England because supply chains were generally shorter north of the border, with petrol only having to travel from the Grangemouth refinery in the busy central belt.

Its chairman, Brian Madderson, told BBC Scotland that the number of sites without fuel had decreased quite considerably since the weekend, when many central belt filling stations were "overwhelmed" by panic buying as concern spread over perceived shortages.

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On 30/09/2021 at 08:58, Bibs said:

Nothing much in the short term. Longer term the engine may adapt to the lower octane and adjust the boost pressure to accommodate the higher instance of detonation. This only really affects forced induction cars too, higher octane is of no use to naturally aspirated cars and makes no difference.

Rachel says hi too :D

 

 

4 hours ago, Bruss said:

Lower octane fuel will reduce performance. The engine is modified by Lotus to give more power by using the octane level recommended. The modifications will have included compression ratio, valve timing and lift, as well as spark timing. To avoid flame front detonation Lotus also use over-fuelling to quench the flame front - all standard practice in performance engines. The lower octane fuel may operate safely but there will be a performance hit as well as a lower mpg (the engine will be running less efficiently). Whether it will be noticeable on the road is another question. At what point the ecu learns and keeps the reduced settings and then needs to be reset when you go back to higher octane fuel, only Lotus knows.

So now I'm a bit confused... should I be putting in higher octane fuel or not in my 2010 NA 🤷‍♂️.. why would Lotus recommend it if it made no difference or wasn't important to some degree???

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I have no idea what Lotus recommend for the NA. Either fuel will be safe though.  For the supercharged car 95 is the minimum but 98 is better for maximum performance.

This is the LOTUS web site

 

https://www.lotuscars.com/fr-FR/fuel-compatibility/#:~:text=Ethanol E5 %26 E10 – A mixture,use 95 RON unleaded petrol.

 

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2 hours ago, mg4lotus said:

On Wednesday it found the number of dry sites in Scotland had reduced to 15% while the UK figure was 27

So I am due to travel up to Dumfries on Tuesday for couple of days 

I need to fuel up in east mids and that’s tricky however do worry I can’t fuel up for my return trip back home ?

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I suspect by next week it will be a non-issue and you will be able to get fuel from pretty much anywhere.

I've been running normal unleaded in my 2010 NA and the previous owner also used it and recommended me to use it.

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I use normal unleaded in my NA and have no issues at all.  So fill your boots, or should that be your tank?

I will however be filling up the Evora's tank with super unleaded for its lay up over the winter, especially so as super is still E5, therefore slightly less hygroscopic I guess, and will do the same when I put my 2ZZ powered Elise S3 into winter hibernation as well. Hopefully by then I won't need to play petrol pump roulette anymore at the filling station!

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Lover of everything Lotus Cars and proud owner of production Evora No.75 (2nd UK customer specced car by VIN). Originally from the Far East....of Anglia, I read black box data for a living so that could explain a lot!

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This thread had me so confused until I realised UK regular unleaded is 95 octane!

Our regular crap here is 91, and I’d never put that in my car!

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Exactly, the 'only use premium fuel' label in the car I think is for the US where they get sludge in their pumps.

 

I believe almost most are now 97 minimum in the UK. Used to be 95. Premium now usually 99+

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Octane numbers in different countries aren't comparable, there are many different systems to measure/display around the world. 

https://en.wikipedia.org/wiki/Octane_rating#Regional_variations

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88 Esprit NA, 89 Esprit Turbo SE, Evora, Evora S, Evora IPS, Evora S IPS, Evora S IPS SR, Evora 400, Elise S1, Elise S1 111s, Evora GT410 Sport

Evora NA

For forum issues, please contact the Moderators. I will aim to respond to emails/PM's Mon-Fri 9-6 GMT. 

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On 01/10/2021 at 14:28, Cdm2018 said:

So I am due to travel up to Dumfries on Tuesday for couple of days 

I need to fuel up in east mids and that’s tricky however do worry I can’t fuel up for my return trip back home ?

So I came down from Scotland on Friday. Zero issues with fuel. Arrived in Rugby where my daughter has bought her first house and no issues with fuel. Have seen no one queing and fuel stations have fuel. Filled up and limited to 30 litres but no issue.

So real experience. Meanwhile the media, militant haulage organisations and [email protected] are telling me there is no petrol. I guess I'm just lucky as even after the 400+ mile down I have a full tank!

Alcohol. Sex. Tobacco. Drugs. Chocolate.  Meh! NOTHING in this world is as addictive as an Evora +0. It's not for babies!    

The first guy to ride a bull for fun, was a true hero. The second man to follow him was truly nuts!   

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4 years ago there were some piston failures on Evora engines in Italy, which was ahead of UK in going to E10 unleaded and even E15 unleaded. There were suggestions it might be due to the petrol used as there were at least 4, maybe 10, and few outside Italy.   https://www.thelotusforums.com/forums/topic/88707-v6-piston-failure/

That led me to do some research into ethanol additives.  Basically, ethanol contains less energy than petrol so will give less power and worse mpg. It also acts as a solvent on some plastics previously used in fuel lines, fuel pumps and fuel tanks - such as the plastic tanks on M100 Elans.  Later cars have used plastics that can handle the low %ages of ethanol, earlier cars did not.

Still don't know how the Evora engine failures occurred though low octane E15 may be beyond the capability of the knock sensor and ECU to compensate so pinking and high combustion temperatures occurred ...  possibly?  Lotus Bulletin says "Do not use Ethanol blends with a higher concentration than 10%"

Anyway, it seemed to me it was to be avoided as much as possible purely from 'less power, worse mpg' aspect. I'd use it if it was the only way to keep moving but only part-fill and top up with E5 Premium at the first opportunity.

In 2017 I took my M100 Elan SE (with Everest Chip) on track at Castle Combe via the Club Lotus Track Day and arrived with 1/2 a tank of Shell V-Power. I had a lot of fun but used a lot of fuel so during the lunch break went to find a filling station. Found a Texaco on the A420 but it only had 95Ron so filled up as many Elan owners had said they used 95 (before E10 put paid to that).

I cut short the afternoon track session because the car was not going like it had in the morning, so wasn't so much fun, and with the Everest Chip increasing the turbo boost to around 1 atmosphere I suspected the Knock Sensor was working overtime ... an interesting 'back to back' test forced upon me by circumstances. 

 

Phil           Leave me alone I know what to do - I think. 

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