Many refineries do not have the capability to add ethanol to the 10% limit as it is added immediately prior to export, whether that be road, rail or pipeline. For instance if it were to exceed the maximum limit (10%) it would have no option but to reprocess at great expense as ethanol then creates greater issues through the crude units. I suspect (and will confirm) that the 10% ethanol injection will be significantly lower than 10% to allow for process fluctuations.
The Esso super 99 ron has no ethanol in it as stated on their website but they still have to mark it as E5. I know this as I checked earlier and treated my NB to a full tank of it this morning.
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well consider ourselves lucky… the US of A will implement E15 
27% ethanol in gasoline in Brazil for over a decade. Do they have any NA/NBs in Brazil? It would be interesting to hear if they’ve had any problems.
https://www.rapidtransition.org/stories/the-rise-of-brazils-sugarcane-cars/
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Already been using E85 for a long time.
MX5s need converting, but they are doing so:
Note, as stated earlier in this thread, Mazda in the US has said since at least 1995, E10 is absolutely fine in 1.8 NAs. There is no discernable difference in the fuel systems of a US market Miata, a Japanese market Eunos Roadster and a European spec MX5 of the same vintage. So curious why Mazda Germany are saying a single tank of E10 will irrersibly damage a NA engine and why Mazda Japan has told Mazda UK to tell the UK government that E10 should not be used in NA and NB MX5s.
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I was running E5 on my mk3 2.0 since I bought it almost 2 years ago but now it’s £1.90 per liter where I live in London have been using E10, obviously E5 is the better stuff to use but it doesn’t go far in a 2.0 engine from 2007. E10, my car is remapped 4-1 and it does not seem too happy with E10.
It drives fine but a little be hesitant if you come off the throttle pedal and reapply it and it’s a little bit lumpy in the lower revs. Probably stuff that would not be noticeable to anyone coming from another car and jumping in my nc1 but after using E5 for so long I notice quite a different with E10.
I don’t see the prices coming down so will look for something more modern that more economical.
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We do have. Very hare, but imports from USA. As any other car from same era that I had the opportunity to drive, no issues at all, but the cars that were Brazilian made/assembled or factory imported did have a different ECU mapping, reducing the power due to the high count of Sulfur in our petrol. But, me personally, am more interested in the rubbers getting brittle.*also if your car sits in the garage, is a no no.
In Brazil as we also have fuel that is 100% ethanol (preffered by the home made turbos). So in general I think that is good if the only change is the added ethanol. *more naturally cleaning properties, but less lubricant.
I will give it a go giving it 2 tanks before my MOT and see how it goes, post back here.
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I was using E10 in mine which is mapped when I first bought it last year. After the first few months mine was noticeably rough running especially on initial start up and idling. Changed to E5 mainly Sainsbury’s Super Unleaded, @97ron, not the full on stuff like Shell or BP but it’s running much smoother now.
I’ve also put it in my daily driver, that has the 1.2TSi engine, runs nicely but I reckon like the NC I get less mpg.
It’s all about the smiles per gallon though in the NC so I’ll stick with the E5 for now.
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The price difference between regular petrol and premium petrol is 12.22 pence per litre (prices from the RAC web site) which is 55.54 pence per gallon.
At 35 mpg that’s 1.6 pence per mile.
Unless you are covering mega-miles it really is a false economy to use anything but premium fuel in your MX5 in my opinion. I will continue to use Shell V Power in my MX5 which makes the most of the performance and gives more miles per gallon.
That’s a win win BTW.
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Never thought an 1840cc NA engine would be sensitive to E10, but mine proved so last week.
I’ve the 4 PIN coilpack, and one of the PINS powers the tacho. It’s one of the first possible signs of a failing coilpack if the tacho starts to flutter or waver. Which is what happened sitting at lights last week after I could not get E5 and popped a third tank of Supermarket E10 into a virtually near empty tank.
Except, it was not the coilpack but the engine revs actually dipping and fluffing.
My heart sank…please…not an engine issue.
Anyway…guess guess? Filled it with 99RON 20 miles from home, and it’s back to it’s raucous sweet self. But, I added a spare bottle of Forte cleaner to the tank I’d had for a couple of years…just to say “sorry pal”
Who’d have thunk it? An NA not happy with E10. I’ve used it in the past, but it must be a different formula now. Any how, it sucks and I won’t touch it again. TBH, the price differential to me is irrelevant.
Being retired, a tank does me more than a month. I’d not like to be a regular commuter these days though. Cost of keeping a necessary vehicle on the road is crippling people never mind the raft of headline Cost of Living impacts. I’m not smug. Just worried about folk like my son, nieces and nephews with mortgages & needed cars.
Paying off our son’s mortgage next week.
Then he can use the disposable cash for his retiral. He does not want it but he’s getting it.
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Can I reply back to myself? 
So, here I am 3 tanks after and very happy, not sure if it is better or if it is just the new MOT vibes but, drives beautifully, drinking a little bit more, but all good.
I do think that on a healthy/stock car, it should be fine.
I always use Shell, as it a nice place to bring a car around Frome.
Cheers!
Had my car from new in May (2.0l). I’ve tried the regular E10, as well as 2 of the premium E5 fuels; Shell V Power and Tesco Momentum.
I cannot detect any noticeable difference in economy, performance or driveability in any of the fuels.
I’m doing 200 miles a week, so the difference in cost is significant, and for me, no point in paying it, I’ll be sticking with E10 from now on.
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I ran my NB 1840 on E5 up until recent sad sale and it purred, wouldn’t bother with E10 myself.
My sole drive 124 Spider Lusso Plus is fed Esso E5 and never skips a beat!
Donkeys years back; my First 5 an NA ran a bit flat and tried Shell premium and it regained it’s mojo almosr instantly.
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Nevertheless, the inaccurate information put out by Mazda UK is costing drivers. Think I need to push them more, and brush off the parts number differences (or lack of) between Miatas, Eunos Roadsters and MX5
US versus Japan market part numbers, fuel system, 1996 MY
Work in progress.
The only real difference is the fuel filler arrangements. Everything else checks out with respect to part numbers
This stemmed from a warning placed in the 1994 Miata (US market) owners manual
eg. Use of 10% ethanol will not void the factory warranty
For a strong statement like that, Mazda must have felt confident in the resliance of the parts in the fuel system
To a query I placed witbh Mazda UK, the initial response was:
Thank you for your email. I have checked with our Technical Support Team who have confirmed the information we have from Mazda Corporation states that for vehicles sold in Europe, only vehicles first produced (Not registered) after 2002 are compatible for use with E10 fuels.
I can confirm that vehicles sold in the US markets are subject to very different emissions laws and therefore differ in specification. Unfortunately, we do not have details of these differences as we only have access to the information relating to vehicles produced for sale in Europe.
Rather alarming lack of knowledge. Followed by
We think the misunderstanding here is because the broader statement simply quotes the 2002 date, which relates to new model types introduced from this date – not individual vehicles registered from this date. For individual vehicle lines, the factory supplied us with the information shown on the DfT’s E10 compatibility tool which is also shown on the Mazda UK website.
To re-iterate, the information shown on the Mazda UK Website and within the Government’s E10 compatibility tool is correct for all vehicles that were originally built to UK specification. Unfortunately we are unable to confirm whether your understanding of the similarities between the Miata and the MX-5 are correct as we do not have this information. For non-UK models we would recommend that reference is made to the owner literature supplied with the vehicle to determine the correct fuel type.
They “think”?? They sent the UK government the badly worded statement from Mazda, which created the confusuon for 2002-2005 owners.
I just need to populate the sheet with EUDM part numbers.
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Spreadsheet updated with European part numbers (click on link). As expected, there is no real difference in the fuel systems of a 1996 Eunos Roadster, 1996 Mazda Miata and a 1994 Mazda MX5 (Europe) contrary to Mazda UK’s statements.
Fuel injector seals, hoses, fuel pumps, fuel filters, are all the same.
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Its a pity no one from Mazda UK could come onto the thread to gve their side.
Just a heads up as I found nothing about this through searching the forum.
The company that makes Valvemaster and Valvemaster Plus (lead replacement fuel additives that are officially approved by the FBHVC) now have a product called Ethaguard Plus for modern classics (safe for cars with or without catalytic converters that were designed to run on unleaded).
This is a fuel stabiliser. If there is any issue (not sure if there is) with seals and rubber bits, this won’t help that.
They should do this in £3 1-shot 50ml measures
Interesting video:
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The SkyActiv-G engine doesn’t like E10 at all. Much lower power (having to change down for hills where you normally wouldn’t) and it burns a bit more of it.
Not an MX-5 issue (and probably never will be, since I doubt the engine with all its ancillaries would physically fit) but I don’t know how the SkyActiv-X engine compares on the two fuels, since it depends to some extent on compression ignition.