Mazda RX-8, fuel conservation?

[mariner2]

The Mazda RX-8 is notoriously thirsty, but is there anybody that knows the most efficient way to drive it?
I've had mine a while now, just had it serviced and asked the question at the mazda garage in Braintree.
The guy said to put the higher octane 98 ron fuel in it and drive it HARDER, keeping the revs up between 3 and 4000 . . . I did this and got my lowest mileage EVER for a tankful, 221 miles before the light came on.
I went back to 95 ron and am keeping the revs right down now and I think I'm going to get past 300 miles for this tank.
It just seems strange that nobody seems to know, even their own garage that services them?

[mariner2]

Ha! I was wondering what it could have filtered out!
Yeah, it seems quite happy to be driven at 35mph in 5th gear . . . .

[mariner2]

I'm getting 16-18 mpg but will beat that this time, though this involves lots of rolling up to junctions and roundabouts and really concentrating on anticipation so as to keep braking to a minimum.

[eltelioni]

First of all, don't listen to people who have never driven an RX8. And I suggest you don't consult that dealer again - the advice about 98RON fuel is completely wrong. Some piston engines benefit from it because it allows the engine management system to advance the timing and squeeze out a little more power. The rotary engine cannot advance the timing because there is no point sparking before the "cylinder" has reached the spark plug. Don't waste your money on that expensive fuel.

The advice on revs is reasonable. Keep the revs above 3000 if you are accelerating - like most petrol engines, the rotary is inefficient if it is labouring. If your cruising, then you can go to a higher gear with the revs below 3000. By the way, the rev counter is misleading. It indicates the rotational speed of the output shaft. The rotors are only going at 1/3rd of that speed. So the rotor rev range is 250rpm (idle) to 3000rpm. At idle, the rotors are going round at a mere 4 revs per second!

Unfortunately a rotary engine will always be less efficient than a reciprocating engine, but it can be tuned for economy. However, Mazda built a sports car, so it is tuned for performance. The RX8 uses a Wankel engine because it is the size of a shoe box and very light. That allows it to be positioned well behind the front wheels giving the car excellent balance. It is also powerful. 230bhp from 1300cc.

So, how can you save money on fuel? It's easy, thrash the bollox off it because that is what it is designed for. Just do fewer miles!

[ChuckFickens]

don't take it to a dealers in Braintree.... they are all a bunch of strange ones from that town you know ;)

(I'm allowed to say that.... it's where I grew UP BTW ;))

[eltelioni]

mariner - have you looked here? http://www.rx8ownersclub.co.uk/forum/

[Toureman]

Your already doing the best you can by trying to avoid braking and not accelarating hard.

The guy at the garage is a numpty!