Rotary

Asked by Oct 08, 2008 at 12:14 PM about the 2002 Mazda RX-7

Question type: General

Based on practicality and fuel consumption,which one is a better buy?An rx7 or an rx8?

14 Answers

7,515

Really as far as fuel consumption they are both horribly inefficient. The benefit of a rotary is that it is light weight and compact, but that's it. A 1.3 L 13b is actually closer to a 3.9l in reality, and it performs as such. You must remember that the rotor acts like 3 pistons and cylinders.... They get away by counting the volume once although if they treated it like a piston engine the volume would be the total space through which each compressing face travels. There are three compressing faces on the rotor, but they don't count it as such, instead they only count one face. A cheap technicality which is why the displacement of a rotary is considered different by different bodies. Most racing organizations class it as a 2.6L... Why they decided to double it is beyond me, but it's a decently fair classification. As to your question it depends exactly what year/model you look at as there were slight variations. I suggest looking around fueleconomy.gov for your answer. P.S. I love the rotary motors, but I hate the line of bullshit about it being a 1.3L in which case that is the worst 1.3l in terms of efficiency ever.

1 out of 1 people think this is helpful.
90

Can't say about fuel consumption, but the RX-8, being a 4-door, is more practical.

2,985

id rather have a rx-7 the new rx-8s are watered down and ugly.

45

On your requirements Rx8 is more practical and will be a better daily driver car. If you want good fuel economy stay away from rotarys in general. Rx7 is a true sports car. Rx8 is more of a sporty car. The 1.3 liter engine acts as a 2.6 liter engine not a 3.9 because it is only making power when with two sides of the rotor not all three. I have a rx7 if you want any more info on them just add me.

2 out of 2 people think this is helpful.
805

I cant say more on fuel consumption then has already been said...the RX7s, wether FB, FC, or FD all just consume as does the RX8. For reasons of practicality, I would go with an RX8 for another reason that has yet to be mentioned, reliability. The FB was known to be incredibly unreliable, and the FC and FD got steadily better but are still not great and honestly the FD, especially the twin turbo version, its not really that great as a street car (and by that I mean daily driver). The reliability and driveability where mostly resolved on the RX8 although it remains slightly more unreliable then lets say a BMW M3 or other cars in its class. As well said by someone above, the RX7 (FD) is a sports car, the RX8 is a sporty car. One last point to make on any Rotary motor, there are many mechanics, myself included who could not even tell u where the fuel injector is (yes im exaggerating...but close enough to). So there are many mechanics out there that will not work on rotary engines or will charge a ridiculous amount of money to do so. I checked in my area before buying one and found that there was really no one except Mariah...and they didnt service the cars, they only did high end mods (This was for drifting and I ended up building a VQ swapped silvia). So overall, the RX8 is a sporty car, itll go on the track stock, although I dont know how well it will perform, its going to be decently reliable, its not going to be great on gas, the interior will fit 4 people, but not comfortably, and dont expect to go buy a washing machine or a fridge with it

1 out of 1 people think this is helpful.
5

The RX-7 (depending on generation, turbo or NA) suffers from poor MPG, as well as the RX-8. Although I believe the RX-8 is a better buy because it is newer and Mazda has a 8 yr Warranty/160,000km specifically for the RX-8. However If you do decide to buy an RX-8, I would avoid the 04 models. Especially with AT, they tend to have more issues than later model RX-8's.

45

rx-8 it was designed to be more fuel effient than the rx7 models they were designed for power.

5

Horribly inefficient? The 3rd gen RX-7's produced around 250HP at 20-25MPG (stock, depending on the year). That's decent performance by any means. And much better than the 1st gen's which produced 90-130HP depending on the year at the same approx fuel economy. The RX-8's? It varies from year to year but I'm sure the last few years they've been rated at 205HP for automatics and 240-255HP for standards - at 35MPG. 35 is certainly not inefficient for a high performance vehicle. (numbers are highway MPG) Another advantage is that although they don't have much torque until the 3-6k rpm range they seem to get the same mileage weather you drive them conservatively or whether you push them hard. performance tuned [url=http://www.insixthgear.com/]cars[/url]

7,515

mate looks like some of your mileages are a bit off there... The mileage for the rx8 appears to be km/gallon highway... All years of the rx8 have hover around 22mpg highway or 18mpg combined, which is almost identical to the 3rd gen rx7s...

45

93 RX7 owner here, the boosted models (86-91 TurboII and 93-95) are the least reliable, but most efficient as they get more power from similar amounts of fuel. The first gens (79-85) are actually fairly reliable cars, as are the NA second gens, and the boosted models can be reliable if you get a standalone ecu, do the reliability mods, and add meth/water injection, I'm lucky to get 13 around town on my modified 93, but other owners get as much as 17 on stock ones. My cousin has an 86 GXL on 220000 miles and the original motor, and my roommate has 150000 on his 80 with the original motor, neither have been rebuilt. But for practicality, fuel consumption, and reliability, you can't beat the RX8, four dours, a friend gets 18 around town in his, it's decent in the snow with good tires, and it's still fun to drive

45

oh, and as far as power goes, the RX8 puts about 210 to the wheels, about 240 at the crank, and the third gen (93+) RX7 makes about 220 at the wheels, the first gen is around 100 at the wheels, the GSL-SE first gens (84 and 85 non-carbed, 13B) and NA second gens make about 120-130 at the wheels, the turbo II second gens make 160-180 at the wheels

waht kind of problems do the 04 models have

45

ur freakin funny man. no torque untill 3k the damn motor revs to 3k almost instantly! u can rev to 3k take off and have your torque all the time and 3k is actually a low torque! read more about rotaries before u open ur moth. that goes for all of u guys on here! no disrespect but u all sound retarded!

1 out of 1 people think this is helpful.
10,645

The RX7 was for going fast the RX8 was for changing engines.Buy a RX8 dirt cheap in 2016 The Wankle engine was a Fail.

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