Chaps.
Which to use? Super or normal?
I’ve tried both (various brands) and can honestly say I haven’t noticed much difference.
I tell myself the Super makes the car feel better, but maybe I’m justifying the extra cost to myself!
It’s my daily drive, of about 20 miles round trip, and for fun.
What has been your own experience?
Rick.
Comes up regularly this, it’s best, it’s not, supermarket, or not, fuel a big debate.
I just stick with good old Asda cheapo, 95 Ron of course. 
Good question.
I have the same engine and it does have a knock sensor, which means that the super unleaded should allow the ecu to apply more ignition advance before pre-ignition is detected.
This ought to mean more power but whether it’s enough to be obvious is questionable.
If it is giving more, it’s probably just a few bhp and you’d probably be hard pushed to feel that.
I have fitted a Pipercross high flow air filter and generally use the higher octane fuel so I feel I am at least allowing the engine to achieve its maximum and I can convince myself it feels better but I know I could well be deluding myself.
Some people reckon that the dearer fuel pays for itself in better fuel consumption. I’m very sceptical about that, so I’m sure you’re at least saving money.
If you have a knock sensor, the ecu will adjust itself to the 95. If you don’t, the ecu will be optimised for 95 anyway, so higher octane fuel will be wasted, unless its the extra additives you’re after but they do come at quite a high price.
Allegedly, in some areas at least, the different brands of fuel all come from the same road tankers…
From what I understand, Unless the car has been remapped on 99 it will not take full advantage of the higher octane. However even a standard map will try to advance the ignition to run clean and a higher octane fuel will allow this and may return slightly better mpg.
Mine was remapped on 99 so I try to use that.
The otherside of this is alot of JDM imports are factory mapped to expect 99+ octane and have to be remapped to stop engine problems if they are run on 95.
Remapped on 99 and have never used anything other than BP Ultra to fill up.
From what I understand, the more modern your car, the lower octane fuels are quite adequate - so an ND should be fine on the cheap stuff.
Our first MX-5 was my wife’s company car in 2011, and it seemed fine on normal fuel, in fact we didn’t give it a second thought. But when the company car 5 had to be returned at the end of the lease period, we opted for a VW Scirocco as its replacement. However, we soon discovered that we missed topless motoring so much, that we looked around to buy another 5 to have just for fun. Unfortunately, we couldn’t afford a new model, and we settled for our current 2008 2.0L Sport Coupe (PRHT). It absolutely hated cheap petrol - it seemed very lumpy, and was not happy at all, but a tank of Shell V-Power cured everything, and now it is my fuel of choice. It doesn’t matter that it is more expensive, because we don’t do that many miles in it anyway.
So, I would suggest that for older MX-5s, Super is the way to go.
In the end though, you pays you money and takes your choice !
Why BP?
Favouring VPower is not uncommon, Esso 99 used to be low on Ethanol but I’ve never heard of any great advantage with BP
I can’t say as I’ve seen a fuel saving from using Super unleaded. But I haven’t done a long run recently to compare.
I’ll bung in some 95 today and see if that makes a difference.
Don’t get me wrong, if Super is better then I don’t mind paying for it.
Right, off for a blast in the sunshine.
Hood down, as usual, (even at 5 in a morning…)
Rick.
My 1991 Eunos is much better on 99, prefers Shell. My ND doesn’t seem to notice the difference so it gets Tesco 95 most of the time. When I had an NC PRHT, it got 95 all the time.
It’s not just about the Octane rating, though, is it?
The better fuels (e.g. Shell V-Power) tend to have a better package of detergents included. When evo magazine did a teardown of two engines of similar mileage, one of which had been run on V-Power and the other on cheap fuel, they found significant differences.
As far as different fuels being delivered in the same tankers is concerned, that’s because they all get the fuel from the same refineries, and the additive package which differentiates the fuels is only added in the tanker.
The additional cost of a more expensive petrol is lost in the noise of the running costs of a car - when you factor in depreciation, insurance, servicing, VED, MoT tests, etc, etc then unless you are doing stellar mileage it’s not going to make a material difference. Personally, I only use V-Power in all my cars (although my wife uses regular Shell in her Lexus IS250).
+1 for what Philip said. It’s about the cleaners and additives. I only use premium fuel in the MX5 to keep it in good condition. Any fuel consumption benefit is a bonus. ( I could always by a Honda Jazz if it bothered me that much).
I have an NC2 1.8 and use Tesco Momentum, the tickover is smoother and it appears to pick-up better compared to 95RON. For the difference in cost over 3-4k miles a year it doesn’t increase my outlay by very much.
I like BP Ultra… 
I have also got a 2008 2.0 sport PRHT, and it runs fine on any fuel. If yours is rough on standard, was it a one off bad batch of old fuel? Maybe injectors have cleaned themselves on VPower? Have you tried cheap fuel since?
I did give my throttle bodies a spray with cleaner and put a new air filter in it, and it runs sweet as a nut on Tescos 95.
I’ve put some Morrisons cheap stuff in. I’ll see how it goes.
I originally used Tesco/Morrisons 95 and it felt ok, having now run it on VP (amongst others) for a few months I try and see if anything is different.
Rick.
Hello Mc Trucky,
I’ve not tried cheap fuel since that time. I don’t always use Shell V-Power to be honest (it all depends what is around when I need to fill up), but I always now use premium of some sort - it’s even happy with the hot stuff from my local Sainsbury’s !
I having a NA 1.6, NC 1.8 with BBR conversion would always go for either V Max or BP ultra. I worked in the oil industry for a number of years, ok supermarket fuels are ok but they lack the addiditives that the majors have spent millions over the years to develop. So Super leaded any time, I do feel the benefit. If money is the issue just fill the tank with super every three or fourth fill.
Fuel economy is of course something owners can actually measure but a lot more people seem to have opinions on how they reckon their car behaves than actually check it.
Some cars do indeed get better mpg on high octane fuel, but it tends to be a modest improvement so it’s less common for it to pay for itself. Our newest car is a little Fiat Panda. That model was part of a major test of 99 vs 95 octane fuels and showed gains of around 3% in mpg but of course 99 RON petrol is more than 3% more expensive.
By contrast my first Mk.1 1.8 didn’t care at all what kind of petrol you fed it. I had a long commute and kept note for years of fuel type, litres to brim it and odometer reading, so i could chart mpg vs fuel type very accurately. I could see summer vs winter trends, I could see where the school holidays happened (improvement due to reduced traffic) but it absolutely didn’t make any difference whether it got supermarket 95 RON or BP Ultimate or Shell Optimax or whatever.
I always remember our much loved split screen VW camper (have you seen how much they fetch nowadays?) I occasionally used to fill it up with the very best fuel, Shell. Back then if I remember (I should I used to be a pump attendant, remember those?) we are talking early 70’s it was I think 5 star and other selections were 3 star, 4 star, could be wrong??
Anyways it went like stink on the top stuff but the mpg went way down, the engine sounded and just seemed more happy on it. Sadly I couldn’t afford to keep running on that, it was around 35p per gallon.
I could be wrong on that too such is my memory.