I`ve just noticed the Hubs have gone back to four stud, they were five stud on the mk3. Weight saving most probably I would guess.
yes, its been thus since we first glimpsed the test mules many months ago…
Maybe it’s whats in the parts bin? Sharing common parts with Mazda 2, 3 and 6?
There is a video where a Japanese bloke goes over various aspects of the chassis “Skyactiv Chassis” and he states that the 4 stud wheels are for weight saving.
On a car almost weighing 1 ton. What is the weight of 4 studs? The weight of that stud is probably less than the differences in the bodyweight of drivers.
Yes it’s a bit hard to believe but 4 studs probably means a smaller pcd and therefore smaller hubs can be utilised, all in all that could well add up to a few kilograms.
It’s still nothing compared to the weight of a large driver, or even that of a spare wheel.
I have always thought the Mk3 should have a spare in place of the large exhaust silencer but I am not a designer or weight saver.
Mazda do call their weight reduction tequiques their “gram strategy”…
Hubs and brakes explained at about 5mins onwards.
Thats not quite accurate, you can have a very small pitch circle diameter with 5 studs. No matter what the diameter you just keep the 5 studs 72 degrees apart. I’ve been messing around wit a CAD program I’ve got to see how “theoretically” small I can go? And if the studs have a diameter of 10mm, you can still fit 5 studs in a pitch circle diameter as small as 17.5mm, which is a crazy ratio as I cant see why you’d want the PCD that small in comparison to the stud size? I suppose the minimum PCD depends on the strength of material in between the studs? The amount of material left in between 5 studs would be 0.9mm, with 4 studs 3.6mm.
There are benefits to reducing the weight of the wheels/hubs etc over other parts of the car.
http://en.wikipedia.org/wiki/Unsprung_mass
I don’t really buy into Mazda’s “gram strategy” though. There are many places where they could have saved weight more easily. For example, was it really necessary to have such a heavy exhaust back-box?
Unsprung mass is important - which begs the question - why do many newer sports cars have these huge (and highly vulnerable to kerbing) alloy wheels? I find them very ugly as well and the low profile tyres cost a fortune.
One of the main reasons that I didn’t buy a Porsche Boxster is that I object to the idea that a set of tyres costs £1000 and doesn’t last long.
I realise you say “theoretically” but the problem there is you have no room for the nut, or the socket to remove the nut! I’d say the minimum is around 90mm PCD for 5 M10 studs if you are tightening one nut at a time or 120mm PCD to allow a 5 socket headed tightening machine to tighten all simultaneously (as they use in the factory).
Surely the best way is to have only one nut - a la the old knock on type!
Originally Mazda were saying the ND would cost no more than the current model. However Mazda UK are now saying £20k upwards.
Given its niche as a fun (and mainly 2nd or 3rd car), a higher price than the current model might not be a good idea.
The same applies to the brilliant Toyota GT86 which has only sold around 3500 cars since launch in the UK, much less than expected.
One thing that amazes me is Japanese car pricing, there is no logical pricing structure for an MX5 built in Hiroshima, in 2007 there were 240¥ to a pound and the car was almost £20k, by 2008 there were only 125¥ to the pound but they managed to keep the price the same, either they were making a HUGE profit in 2007 or a loss in 2008 
Currently there are 170¥ to the pound but prices are still the same, the estimated £20k price is just a guess at what we are prepared to pay, you only have to look at the proposed US price to think we might be getting a tad exploited.
I think you will find the MX5 wheel nut size is 12mm, working in engineering I am used to allowing enough wall thickness and load area on threads and flanges, most of my applications do not have the extremes of torque, temperature and weather either.
At least the MX5 has something different about it. I took the GT86 out for an extended test drive on my own. I ended up taking it back after an hour, dropping the keys off and walking away without an ounce of regret. Obviously a very capable car, and I love the looks, but so, so uninspiring to be in IMHO.
The second I sat low down in the MX5, dropped the roof and looked over at my 4 year old daughter’s face beaming with delight it felt a bit special, when we pulled off and went for a little spin out I knew I’d have one, it wasn’t the speed or the handling, but the experience, something I’ve not felt since I went in a mates Spitfire.
Japan has had deflation for years. Which is presumably why the pound buys fewer yen now than before.
Given that I would want the 2.0 litre paddle shift with folding hard top and metallic paint - it could cost me £24k. Can’t see that happening!
Perhaps I’ve not been paying enough attention but this is first shot I’ve seen with anything other than a red car…
Was it the Japan launch ?
and in white, just for you
On first glance I thought it was a picture on the background
Two page write up in this months What Car mag.
My initial impression is that the side and front views didn’t look that far removed from MK3.5. Rear obviously different.
Hope they put side airbags in the base models, could never understand why the MK3 1.8s never had these.
No doubt in time they will be as popular as ever. I also hope that they have improved the corrosion protection but I guess this doesn’t match with reducing the weight.
I might buy a three year old one for £10k when I reach 65 in 2018!!!