Manual Owners - Taller 5th Gear?

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2008 Mazda5 GT
Before settling on the Mz5, I was looking into a ’07 manual SX4. The 5sp also suffered high revs at highway cruising. In 2008 (2010 upgraded to a 6sp), Suzuki revised the 5th gear on manuals and made it taller, allowing the car to drop ~500 rpm when cruising in 5th. This lowers NVH and improves HWY mpg by about 2MPG (MPG was/is a big gripe about the car), but decrease 5th gear pull by a little. I think this is a worthwhile trade off when you can (and should) down shift if you really want to overtake someone. Members then went and bought and swapped out the 5th gear. Since it was a manual, the gear can be swapped without dropping the transmission.

I have always wondered if Mazda did the same or if the same 5sp tranny with a taller 5th gear existed in another car that can be reused. I think Mazda, being a smaller shop, do a lot of parts bin sharing but there's no way to confirm tech details unless we have a Mazda insider. I do a bit of HWY cruising and really dislike the noise. The MPG improvement (~1-2) is icing on the cake and help to justify/offset the added cost (gas is only going to go higher). Did a bit of searching and found there 'was' (not sure if they are still in business) a vendor that made a taller direct fit/replacement 5th gear. Anyone here looked into this? The posts are kinda old but if they are in business, I would consider it as it pays off in the long run and in other ways (comfort for the family). However, this is only half the battle. One would still need to find a competent transmission shop to do the swap…

http://www.mazda3 forums.com/index.php?topic=47528.0

EDIT: Just re-read and noticed this on post 12 by the OP.. as it is a Mazda stock part... trade secret though. . So this may very well be a different 5th gear from another Mazda... But what? hmmmmm.
Also, some of the math on RPM drops gets lower and lower :p
 
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I would LOVE a taller 5th gear. Looks like that shop's web site is gone though: http://nsnmotorsports.com/

I wouldn't mind tackling the swap (would source a spare transmission first), but it looks like the 3's gearing is taller to begin with? I'm spinning almost 4k by 80mph, while some of those guys are claiming 3.4k @ 80. Maybe just swapping to a 3 transmission would do it? On the other hand- dropping in the 6 speed might be a better option while screwing around with the car's drivetrain.
 
(if anybody is having trouble with the link in the first post, copy & paste, then remove the space - this forum censors out the name of that forum)

That's interesting, if it really is only about $250. With these assumptions: (a) gas is $3.50 per gallon; (b) you get 28 mpg on the interstate now; and (c) you will get 30 mpg on the interstate with this device, I calculate the "break even" point at 27,778 miles traveled... in fifth gear.

What about the '12s 6-speed manual? Will that fit on an '06 to '10 Mazda5?

Also, a high 5th gear ratio is a complaint that I've been reading about for the Honda Fit. Have they come up with a solution?

And when I first bought my 5 I did a little research. Turns out that for EPA mileage, the average highway speed is 45 mph and not realistic highway speeds.
 
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I would LOVE a taller 5th gear. Looks like that shop's web site is gone though: http://nsnmotorsports.com/

I wouldn't mind tackling the swap (would source a spare transmission first), but it looks like the 3's gearing is taller to begin with? I'm spinning almost 4k by 80mph, while some of those guys are claiming 3.4k @ 80. Maybe just swapping to a 3 transmission would do it? On the other hand- dropping in the 6 speed might be a better option while screwing around with the car's drivetrain.
I noticed they closed too but the part that really catches my attention is that this sounds like a stock part from some other Mazda product. Since they are out of business anyway, it would be awesome if there's a way to get in contact with them and to get them to spill the beans on what car and part number they are sourcing. The 6sp is definitely nicer but from what I read on the SX4 forum and briefly described in the other post, the effort to swap out the 5th gear reads like it is a lot less involved than a full tranny swap and can be a DIY effort. Incremental benefit at incremental cost vs much bigger expense in buying a used 6sp + install cost. Btw, I'm spinning ~ 3750 RPM @ 80MPH on 215/50/17 tires.


That's interesting, if it really is only about $250. With these assumptions: (a) gas is $3.50 per gallon; (b) you get 28 mpg on the interstate now; and (c) you will get 30 mpg on the interstate with this device, I calculate the "break even" point at 27,778 miles traveled... in fifth gear.
MPG wasn’t a top priority for me but it is a nice benefit too. However, note that this calculation is flawed b/c a variable ($3.50/gallon) is used as a fixed value. I hate to be a pessimist but we’ve hit $4.00/gal and I’m sure it’ll go higher (lower too at times but higher than not). I still remember the brief stint of $.99/gal in NJ in the mid/late 90s -good old days. This is the same flaw used by anti-Prius fans when the car first came out but gas price has rocketed since and owners are reaching their break-even point much earlier. Trying to make this call is like playing the stock market –you cannot predict it.

I vaguely recall the price for SX4 parts was about $200 so this NSN price (+ some profit) is about right. Again, going off memory (which is not very good these days) the cost for labor was somewhere in ~$300 range so $500-$600 total. Worth it to me to get better MPG, less NVH, and engine longevity (less rotation = less wear); albeit slight improvements.
 
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$4, haha, I wish I could get gas that cheap. Gas is $4.50+ right along the west coast from California to Washington State, and was $5.50 a gallon in Vancouver when I last filled up (15.3 gallons for $85, yes I ran the Mazda 5's tank very low), although it's starting to retreat a bit, $5.38 a gallon now.

I thought about swapping out the final gear ratio as well, but at this point my wife and I need two cars so the 5 may be getting replaced with a new Skyactiv 3 and a used 2000+ MPV, preferably 2004+.
 
I noticed they closed too but the part that really catches my attention is that this sounds like a stock part from some other Mazda product. Since they are out of business anyway, it would be awesome if there's a way to get in contact with them and to get them to spill the beans on what car and part number they are sourcing. The 6sp is definitely nicer but from what I read on the SX4 forum and briefly described in the other post, the effort to swap out the 5th gear reads like it is a lot less involved than a full tranny swap and can be a DIY effort. Incremental benefit at incremental cost vs much bigger expense in buying a used 6sp + install cost. Btw, I'm spinning ~ 3750 RPM @ 80MPH on 215/50/17 tires.

That sounds about right- I haven't paid super close attention to the revs / mph in the last few days, but that sounds correct. I guess I'm not concerned about the labor cost of the swap, just the parts- and the possibility that something would get screwed up or broken during the install and leave my wife without her car.

As for gas mileage, I did the math on my truck before- if I just went from 18mpg to 19mpg on my commute, I would pay back a $500 ECU upgrade in less than a year. It should be fairly similar for the 5.

$4, haha, I wish I could get gas that cheap. Gas is $4.50+ right along the west coast from California to Washington State, and was $5.50 a gallon in Vancouver when I last filled up (15.3 gallons for $85, yes I ran the Mazda 5's tank very low), although it's starting to retreat a bit, $5.38 a gallon now.

I thought about swapping out the final gear ratio as well, but at this point my wife and I need two cars so the 5 may be getting replaced with a new Skyactiv 3 and a used 2000+ MPV, preferably 2004+.

I saw 87 octane at $3.23/gallon today on the way to work. :)
 
Wow! I love to live in Europe. We pay 8.5 usd per gallon, so it's much more attractive to upgrade the gear over here :'(
 
Wow! Yeah, so glad I don't pay euro prices for gas. Of course, if my salary came in pounds or euros, I'd be driving a diesel car too. :)
 
Zombie revival but too good not to pass on to other owners.


The answer in detail with how-to and reference links! The ultimate prize is the .68 gear available in diesel Mazdas overseas (anyone know the gear ratios for the diesel Mazda 5!?).

Folks who live with high gas cost may want to do this. Parts are readily available, cheap, and looks pretty easy to do!



HUGE credit to the guy who posted this.
https://www.youtube.com/watch?v=yJPVmCzTayY&list=PLoNuT5isJSy-vGOOHbZp9jXXremA6R2UX&index=18&t=0s

This video I made shows how to swap the factory .75 ratio 5th gear set on your 04-09 Mazda 3 with a higher .71 ratio set. This will lower engine RPM by about 200 RPM at 65 MPH in 5th gear and should give you a 1-2 MPG increase. There is a higher .68 gear set but it was only available on Mazda's equipped with a diesel engine that weren't sold in the states. I also replaced the 5th gear synchronizer ring since it would sometimes grind. This swap is only for vehicles with manual transmissions.

You can buy the .71 gear set online: http://***********************/crossove...

You can also source it from a vehicle in the junkyard. 97-02 Ford Escort sedans and wagons have this gear and are pretty easy to find.
This is how you remove the gear set from the Escort: http://www.feoa.net/threads/5th-gear-...
You can also get the gears from other Mazda's like the 626 v6, MX6, and possibly the Ford Probe. I'm not sure of the details though.

Synchronizer ring part # gc03-17-265
http://www.jimellismazdaparts.com/pro...
 
Zombie revival but too good not to pass on to other owners.


The answer in detail with how-to and reference links! The ultimate prize is the .68 gear available in diesel Mazdas overseas (anyone know the gear ratios for the diesel Mazda 5!?).

Folks who live with high gas cost may want to do this. Parts are readily available, cheap, and looks pretty easy to do!



HUGE credit to the guy who posted this.
https://www.youtube.com/watch?v=yJPVmCzTayY&list=PLoNuT5isJSy-vGOOHbZp9jXXremA6R2UX&index=18&t=0s

Wowwwwwwwww. Wish I had known about this years ago. :( Custom gear set maybe?
 
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