Mk3.5 vs Mk3.75

Hi all,

I’m finally actually in the market for an MX-5. 

Started looking at Mk3’s 2013+ (approved used), as I thought the 2013 facelift had some internal changes too - but the more I look, the more it seems the change was pretty minor.

What’s the difference between the Mk3.5 and the Mk3.75?    Is it just the chin spoiler, and a bit of throttle mapping changes? Would I notice the throttle fiddling?
In short: is there a compelling reason to go for a Mk3.75 over a Mk3.5?  Seems you can save ~20% by going for 2010/2011 vs 2013/2014.

I’m after a 2.0l, power roof, and leather interior, an a nice example.

Thanks for any tips :slight_smile:

Main reason i went with a 3.75 was because it offered the tan seats and meteor grey mica paint and the chrome grille surround delete on the front along with the squarer non-leaf shaped foglight surrounds. The main thing with the mk3 is chassis and underbody condition and good maintenance regarding oil level and condition. A cherished,low mileage example of either would be a good buy. Look underneath any car you view, preferably on ramps if a dealer car and plan on getting rustproofing done if not already present. I would also check for evidence of rust or water ingress into the passenger footwell behind and above the lower glovebox panel.

Mk 3.75 have the pyrotechnic charges under the bonnet as a pedestrial impact protection feature iirc

Thanks for the tips so far.

Is rust an issue on these cars? I’ve never even considered it on a ~4-6 year old car before - and they have 12 year rust warranties? Aren’t they rust-proofed at the factory? (too many question marks, sorry.)
Probably a good reason to buy from Mazda and get the warranty just in case then.


I wouldn’t get to hung up on either just buy the cleanest example you can find


It will not rot through in say 6 years and that is what the Mazda warranty covers as long as the Mazda dealer has done all the corrosion checks at each service and it is noted in the Digital Service Record which Mazda open to all motor traders to access and update when the car is serviced. If the car is rusty underneath but not perforated Mazda will not repair that damage.

I’m afraid your research has not been good enough as Mazda advise they do not completely rustproof their cars and a letter was published on this forum advising that point from Mazda UK.

You will find a number of good “how to rust proof your NC and ND” on the net as the stone chip applied by Mazda underneath misses considerable areas and the cavities and areas under the wheel arch protectors and behind the grill are not protected by either wax or stone chip.

I assume you have not got the premises to rustproof your own car, if that is the case and you are keeping the car for over 3 years get it rustproofed and budget around £400 for the work.

On the other hand if you intend to replace it after 2 years or so you will probably get away without doing the rustproofing but get that checked on a car lift as a previous poster has advised.

You have been warned and do not think that because it is being sold from a Mazda dealer as a guarantee of there being no rust underneath!

You may find a clean car rust wise especially if you are looking at a Mk3.75

ok - thanks for the warning! heeded!

I’m in my second 3.75, sold the first one in may 2016, missed it so much I bought another in June 2017. Although they were both the same model I think the current one is the better of the two.
There are a few cosmetic mods between the 3.5 & 3.75 but you probably wouldn’t notice unless you knew the models and mk’s.
Had mine rust proofed regardless of what was there from the factory

As other posters have said, the differences between the 3.5 & the 3.75 are largely cosmetic (front bumper / foglights) plus a “more responsive” throttle, pyrotechnic bonnet & a piano black dash trim instead of the 3.5’s aluminium effect item, the wheel centre caps were black instead of silver; also on the 2.0 Sportech you got aluminium pedals & a photochromatic (i.e. auto-dipping) rear view mirror - that was about it.

Personally I think that the 3.75 looks better from the front than the 3.5 (& I’m a 3.5 owner) but - condition is everything & in my opinion there’s very little difference between the two with regard to spec.

Importantly, as other folk have said, it’s absolutely essential to have a good look underneath these cars - the standard of Mazda’s “rustproofing” is laughable in my opinion; also I believe that their perforation warranty specifically excludes corrosion caused by road salt(!).  Also note that, unlike most modern cars, these bodyshells are not made from galvanised steel.

Before I bought mine in 2012 I had a look under a 3 year old example (09 reg) & was pretty shocked at the state of the subframes & bracing members in particular.  Hence mine was professionally rustproofed when new, within a few weeks of me taking delivery as I’d always planned for it to be a keeper - & I’ve never regretted paying for that work.

Having said all of this, don’t be put off - there are many good ones out there which will have been properly looked after without much winter use & probably garaged too - and / or had an aftermarket rustproofing treatment early on.

I see that you’re looking for a 2.0 litre with leather interior & power roof - same spec as mine, it’s a brilliant car - happy hunting!

1 Like

Thanks for the help guys - very useful. Happy hunting indeed :slight_smile: Hoping to acquire one in the next few weeks.

I’ll make sure to check underneath then and look into rust-proofing. I have a slight bias to the 3.75 now because it’s younger and all this rust talk… The car will probably be 4 years old minimum already so hope it’s not too difficult to find a good one.

If anyone knows a good source of MX-5’s in the Beds/Cambs area I’d love to hear about it.


Saw an old thread on a dealer in Saffron Walden - they seem to have lots of newer MX5s:


If you do decide to opt for a 3.5, there’s a low mileage sport tech here

Thanks for that - I didn’t know about this dealer. Any experience?


I only know him from looking around when I bought my current 5. He deals mainly with MX5’s and I believe works from home. I went to look at an earlier model that he had which was in lovely condition, but I wanted a newer model.


Seemed a decent fella but I don’t know any more that that. There’s also in Northampton who deals only with MX5’s, I bought my first one from Dave.

If your after a late car I have a 14plate sport nav done 26k and will be sold with a warranty £12995

1 Like

Update: Just bought a 63 plate 2.0l Sport Graphite (red with black roof) with 21k miles. Immaculate car - almost like new, and checked underneath. Will get rust-proofing quotes now…!

Thanks for all the advice.

Thanks for the offer too @rodders, your car looks immaculate also - I’m just not a fan of white. :slight_smile:

A red sport graphite is a rare beast indeed, congrats.

Where did you come across it?

Like earlier generations of the MX-5, rust is pretty much all due to road salt.  If you garage the car during the winter, it isn’t an issue.  My 5 year old Mk3.75 looks new underneath - it did its first winter on the road but has been put away for the last four.