I just calculated my mileage and it came out to 15mpg's. Is that normal? It seems a little low to me. All I did to the motor is remove the rat's nest/pump, dual pulley, mechanical secondaries, took off all the needless stuff off of the carb like the choke and the linkages, and racing beat from header all the way to the back. I also took out the AC pump and condenser and crap to clear out the engine bay

My next question is about the heater. Is it me or does the heater not heat in our cars. does the heater work only off of the heat given off of the coolant because if thats the case my car never goes past the very first mark on the temp gauge, especially now that I'm in 20 degree weather.

 

all heaters work off of coolant

and 15mpg is not bad

 

Mechanical secondaries...... Keep your foot out of the carburetor.... but 15mph for city driving is good. I usually get 20mph highway with some city.

Heat... Important to have a good engine thermostat, which helps to keeps the engine temperature at normal operating temperature.

John

 

Yes, 15mpg is not bad, it is atrocious!

You should be seeing at least 20mpg for a dead stock car, possibly as high as 25 highway given that you have a freer flowing exhaust. IF you had a choke, and you did a lot of in town driving, then I can see 15mpg since you'd be on-choke much of the time, but you don't. Did you really richen the idle mxture up to compensate? How about when you removed "the needless stuff", wonder if you plugged the carb vent and the carb is lightly flooding. Are the spark plugs more than 6,000 miles old? If so, change them ASAP. Ignore the maintenance guide, change those plugs every 6k.

You probably ned a new thermostat if your engine isn't warming up very much, but then the factory gauge isn't particularly useful. Normal generally seems to be 25% up the gauge with imminent danger about the halfway point and above halfway being "shut off as soon as you can". So before changing the thermostat, backflush the heater core by removing the heater hose from the engine and from the radiator, dig out the garden hose, and spray into the hose that was connected to the radiator. Really flush it out good, several minutes worth of full volume flow. Then go back and forward-flush it (spray into the hose that attached to the engine) and backflush it again. I *really* need to do this to my car because my heat is crappy too. Every car that I've owned, I had to do this, and the difference in heat was dramatic.

You also didn't say what year you had, but if you have manual controls for the side vents, make sure they are in the "recirc/heat" position instead of "fresh air". Mine are stuck in fresh air which is the other part of why my heat sucks.

 

As a point of data, when I had by bog stock 85 GSL-SE I got 26mpg on the highway at 75mph. I had 5000 miles of driving across country to note this

 

A GSL-SE is not powered by a carbureted 12A.

 

What gas mileage did Mazda claim a RX7 would get new from the factory??

12A and 13B?

Anyone knows or has some original sales info? Perhaps an old cag mag article?

 

84 GSL-SE is EPA rated at 18city 29hwy and 22 combined. I'm sure the test has changed since then

 

The thermostat is pretty new(under six months) and I just put new spark plugs in it. I'm gonna try calculating my mileage again but this time I'm gonna drive a bit more civilized. I was driving around with my foot planted alot the last time because I like the way the car sounds at full throttle. Where is the carb vent located anyway. By the way I have a 85 GSL

 

I have an 85 GS and mazda claimed that it would get 26mpg city and 30mpg on the highway, but i'm sure that is with granny driving, and since when has any "claim" been very accurate?

 

Does anyone know at what RPM the Rotary engines are most efficient? Specifically the 12A?

 

LOL is it an auto?

 

The torque peak is 4000rpm.

I'd get my best mileage driving at 4000rpm on the highway. Either in 4th gear in traffic, or in 5th gear in fast traffic.

 

I just calculated my gas mileage after driving around like granny. Still in town thought(lots of stop and go traffic average of about 35-40). It came out to 15mpg again. Well, I guess I'll go back to the way I was driving again. I'm gonna find out what my highway mileage will be when I drive to NY/NJ during the holiday weekend coming up here in a week or so. I should be able to get a good accurate figures since I live right off of I95.