I'm constantly searching for a 6th gear in my t2. There are a few places where I can legally and safely maintain 90mph and It's really working at that speed. For the sake of fuel economy, a 6th gear would be nice. Just needs to be made by getrag or some high-quality manufacturer.

Didn't know that either MRX_Rotary. :)

It's not going to be worth anyone's while to pay for a 6-speed so they can save fuel @ higher speeds. :) I wonder if when getting the tranny rebuilt it would be possible to have the 5th gear ratio changed to .65:1 or something?

Have you considered that it's unlikely the savings in fuel costs will not pay back the cost of a 6-spd conversion within the car's expected remaining life?

since when has 90 mph been legal anywhere outside of montana?

ummm.... well gas right now in california is $2.69 for 91 octane... so I think it will give me money back considering it costs me $35 bux and before this gas hike it costed me only $24 bux. And I fill up every 3-4 days. Do the math... it'll add up man... pretty damn quick too...

Since you have given no indication as to how much gas a 6-spd would save you, there is no math to do. You seem to think it'll be alot, which it certainly won't. Come back when you have a valid argument...

In a straightforward swap, I believe that the conversion would not be cost-effective. However, if someone needs to replace their gearbox, anyway, the difference in the cost of a used 5-speed and a used 6-speed *might* be recoverable, depending on the 6th-gear ratio.

i'm surprised NZ hasn't commented on their fuel prices, which when i found out the other day from my friend Zoe it shocked me. Works out to $5.28/gal for 89, or close to it.

Considering how low the torque on the rotary engine is at low RPM, I doubt that the 6th gear is any lower then our 5th gear. There would be no fuel savings.

It's not quite that high, but it went up again today... :( It's now ~NZ$1.35/L for 96 (similar to your 89 I believe), or ~US$3.60/gal. Relative to average incomes our petrol is still pretty cheap compared to most countries in the world.

It's still a very weak justification for a 6-spd swap, because you're still assuming a worthwhile reduction in fuel consumption, which is unlikely.

For those that are interested in the gear ratios of the RX8, here they are. True 5 speed with 6 overdrive:

Diff - 4.444
1st - 3.760
2nd - 2.269
3rd - 1.650
4th - 1.187
5th - 1.000
6th - 0.843

Well that certainly isn't going to save you any fuel... ;)

Yep, which is why I thought I'd finally post it up :)