Hi all, I am new to the RX8 having only owned mine now for just under a week :ylsuper: .
I live in the UK and own a Winning Blue, 231 6Spd RX8. I went into alot of research before buying one, and I like the car more and more every day! I knew consumption was going to be bad.... But 3 quarters of a tank I managed to get 106 miles. Is this normal?
Im now doing a experiment with the new full tank, not going over 2.5k revs. So far i've squeezed 23 miles out 1/8th of the tank.

What is the most ecanomical way to drive a rotary engine? the lowest Rpm possible??

Many thanks

Well, holding it to 2.5K rpms is certainly not good for this car and will not improve your fuel mileage substantially if at all. The best way to improve fuel mileage is to not let the car idle for long periods, avoid stop-and-go traffic, go easy with acceleration, and keep the engine in the power band which is 3K rpms up. On the open road in 6th gear, try to keep the revs below 3,750--the point at which the ECU commands certain functions to happen that can result in more fuel being consumed.

BTW, you cannot accurately measure the fuel mileage using the fuel gauge. You can get a general idea of mileage, but such gauges are not particularly accurate. Fill the tank, note the odometer reading and do that for several tankfuls. Then divide the total miles (km) traveled by the gallons used for those miles and that will give you a reasonably accurate reading of fuel mileage. You should expect to average ~20 mpg for mostly open road driving. Stop-and-go driving mileages frequently have been reported in the low teens--some lower than that.

do a SEARCH. The fuel topic has been discussed SO MANY TIMES that telling people to search for info has been discussed a billion times already. As a new owner, just about every question you have has already been answered.

OK, I need to clear this up once and for all because I've heard this before. Driving your 8 at 2.5K does not harm your engine...if it did, then at idle we would all be hurting our engines.

The RENESIS has a built in seal that actually removes carbon so the REV it to 9K daily or else it will build up carbon is hogwash.

With that said, that does not mean that revving to 9K does not loosen things up and make the rotary “feel” nicer but certainly driving at 2.5K does not harm the engine when the owners manual actually states that by 45mph you should be cruising in 6th gear which means the car would actually be under 2.5K...more like 2.25K.

So, what I suggest to you is to shift before 3.8K and make sure you are cruising around in 6th gear when you are going 45mph or more.

I don't do this all the time since I like to push my 8 some but I do it enough that my 8 has never gotten less than 249 miles per tank (or 18.6mpg). My lifetime average is 19.2mpg and when I really drove like a grandma to see how high I could get I reached 20.5mpg in all city driving with normal traffic (not too much not too little).

With all that said, I'm not a rotary expert by any means but from what I have heard here driving the rotary at 2K is not going to harm your car nor is hitting 9K.

When my 8 is cold I always shift at 3.5-3.8K (as well when I'm just cruising around), but when I'm more aggressive I shift in the 5+K range (when I REALLY want to play I nail her 9K hot spot often).

Note: If I'm wrong, please teach me...cause again I'm not a rotary expert...only a newb.

If you're "not a rotary expert" why are you making such definitive statements? Certainly idling momentarily at 2.5K won't harm the engine. But lugging the engine for long periods while driving in the higher gears is not good for the engine. The engine should be in the power band in order to not stress the engine and the power band starts well above 2.5K.

Hi all, I am new to the RX8 having only owned mine now for just under a week :ylsuper: .
I live in the UK and own a Winning Blue, 231 6Spd RX8. I went into alot of research before buying one, and I like the car more and more every day! I knew consumption was going to be bad.... But 3 quarters of a tank I managed to get 106 miles. Is this normal?
Im now doing a experiment with the new full tank, not going over 2.5k revs. So far i've squeezed 23 miles out 1/8th of the tank.

What is the most ecanomical way to drive a rotary engine? the lowest Rpm possible??

Many thanks
jimmy jammy- I would strongly suggest that you use Go48's advice for optimal gas mileage. Don't lug the engine at 2k RPM's shift at around 3,500 and remember that the gas tank is shaped quite narrow at the top. That might explain your poor mileage in the first quarter tank. Good luck. Keep us informed.

If you're "not a rotary expert" why are you making such definitive statements?

Did I not leave the door open to being wrong? "not an expert"..."teach me if I'm wrong"...why did you ignore that?

Again, unless some of the rotary brains come in here and tell me otherwise I still think it's OK to drive around town going 50MPH and in 6th gear. IF...that is harming my engine, then this is the last rotary engine I buy.

I didn't know that power band = no stress, last I heard race cars put alot of stress on engines and it's not because they are cruising around but because they are running it constantly in it's power band.

Again, I could be wrong but if my engine dies I'll blame Mazda since they state in their owners manual that I should be driving it in 6th gear past 45mph for optimal fuel economy.

No offense, maybe you know more about the rotary engine than I do...but I still would like to hear more on this.

Did you know about the seal that scrubs carbon off the Renesis? Maybe I misunderstood that...but I don't have the link with me to show you what I mean.

AGAIN...I'm completely open to being wrong, until I hear it from more people I think I'm right on this.

it is ok to drive around town in 45 in 6th gear. but you should still rev it (in gear while moving not free revving) at least once a day once warm. it really is better for teh overall health of your engine. there is no "scraper seal"

jimmy pleae read the sticky thread http://www.rx8club.com/showthread.php?t=61139 and post there if you have more questions

it is ok to drive around town in 45 in 6th gear. but you should still rev it (in gear while moving not free revving) at least once a day once warm. it really is better for teh overall health of your engine. there is no "scraper seal"

OK...agreed with me, agreed with "you should still rev it for the better health of your engine" which I didn't disagree with, but no "scraper seal" agreement?

Zoom44 here is where I got it (thank you google):

Linky (http://www.rotaryengineillustrated.com/renesis.php)

This is what they said:

Newly Designed Seals: Renesis employs a new cut-off seal located between the rotor’s dual oil seals and side seal. This sealing arrangement eliminates blow-by between intake and exhaust ports and prevents carry-over of exhaust gas to the next intake cycle. Side seals are a new keystone-type with wedge-shaped section. Exhaust gas build-up against the side seal can easily cause carbonisation, but with the wedge-shaped or cuneiform side seal, the seal shape is optimised to remove carbon.

...and here is the picture:

http://www.rotaryengineillustrated.com/renesis/renesis14popup.jpg

the side seal is optimised for cleaning carbon build up from itself. it doesnt say it removes all carbon build up or even if it stops all carbon build up against itself. just that it removes as much as possible.

i was actually going to get the same pic;)

So where in the engine does reving high help clean?

This is my first rotary and I'm always willing to learn something new.

the extra heat helps burn it off where ever it is.

I see, how effective are fuel, carb, injector, etc cleaners on a rotary engine? I think we can agree that techron from Chevron has been shown to really keep the combustion camber clean on piston engines...does anyone know if they are as effective on the rotary?

Sorry for sidetracking this thread.... :o:

Ahh... I feel so much better after spending a couple of hours sitting down, using the search button and absorbing all this new information like a sponge on how to treat a rotary engine!! lol

So bottom line is that what i've learnt...

Optimum fuel efficent driving is around 2.5-3.5k Rpm

Rotary engines are nothing like a normal engine (i knew that anyway :p)
and that its actually GOOD to Rev the engine hard, and to drive with high RPM as to compared with a normal piston engine it is bad... I still cant get over that!
I've been treating my new car with such respect and being careful lol...worrying about wearing the engine out, and ive been driving it totaly wrong so far.
And of course letting the car warm up 'n all.... (we all know that one.)

I just need to say what a great help all you guys are, I cant wait for the next time i drive my RX8, that i know now to keep reminding myself its GOOD to redline it, and keep it up in the high Rpm's... thats what driving is all about!

Having owned 4 previous cars, and enojying while you can redlining a few gears, but deep down you know your torturing the engine....Now I am Freeeeeeeeeeee lol

When you start shifting a higher RPMs, you'll unleash a whole new beast in the 8.

I was in your shoe's once...and on some levels still am, you really learn alot here and learn to fall in love with the RX8 and rotary engine quickly.

OK, I need to clear this up once and for all because I've heard this before. Driving your 8 at 2.5K does not harm your engine...if it did, then at idle we would all be hurting our engines.

The RENESIS has a built in seal that actually removes carbon so the REV it to 9K daily or else it will build up carbon is hogwash.

With that said, that does not mean that revving to 9K does not loosen things up and make the rotary “feel” nicer but certainly driving at 2.5K does not harm the engine when the owners manual actually states that by 45mph you should be cruising in 6th gear which means the car would actually be under 2.5K...more like 2.25K.

So, what I suggest to you is to shift before 3.8K and make sure you are cruising around in 6th gear when you are going 45mph or more.

I don't do this all the time since I like to push my 8 some but I do it enough that my 8 has never gotten less than 249 miles per tank (or 18.6mpg). My lifetime average is 19.2mpg and when I really drove like a grandma to see how high I could get I reached 20.5mpg in all city driving with normal traffic (not too much not too little).

With all that said, I'm not a rotary expert by any means but from what I have heard here driving the rotary at 2K is not going to harm your car nor is hitting 9K.

When my 8 is cold I always shift at 3.5-3.8K (as well when I'm just cruising around), but when I'm more aggressive I shift in the 5+K range (when I REALLY want to play I nail her 9K hot spot often).

Note: If I'm wrong, please teach me...cause again I'm not a rotary expert...only a newb.

Idling in low rpm is not the same as under-revving (lugging the engine) in gear (you are loadng the engine in the latter). I don't know much about a rotary engine but in a piston engine, lugging may cause piston slap (just something I read, not sure if its true or not)

Hi rx8wannahave and others - you get 19 mpg !!!!!! I would die for this, my average is 14mpg with many weeks at 6 - 10 mpg (US Gals).
Measure by filling up and noting miles at every fill up since new.
I got my new AT in Oct 2004, love it to bits, but the fuel economy often tests my love for it, mainly because I have to stop for gas every 150 mils or so.
Do the experts out there think I might have an engine problem, I got most Flash updates (I think), I live in the cold NE USA so have to remote start my RX8 for 5 minutes twice a day.
For those that tell me to do a search, I have and not got much relevant information - re-borne threads are not all bad IMHO

I live in the cold NE USA so have to remote start my RX8 for 5 minutes twice a day.
Well when you idle the car for 10 minutes a day, you WILL get poor mileage. Not necessarily that bad, but if your engine is running at idle, whether in your driveway of at traffic lights, you're not racking up any miles while you're burning fuel. If most of your driving is stop and go, that will kill the fuel mileage in this car.

Let the car warm up for a minute or less and then drive off keeping the rev at or below ~3K. That should improve your mileage a little.

Hi Go48 - I agree, while idling fuel is consumed and no miles clocked up, I do occaisionally let her idles for 5-10 mins, but mostly do as you suggest, get on the road and go easy until warm.
However, before I got the rotary my driving pattern with a piston engine was the same. I am quite sure that the piston engine did not suffer such a reduction in MPG because of the idle periods.
Does anyone know if the Rotary is more prone to gas guzzling at idle than a regular piston engine ?? Can't solve the problem I know, just curious.

Hi Go48 - I agree, while idling fuel is consumed and no miles clocked up, I do occaisionally let her idles for 5-10 mins, but mostly do as you suggest, get on the road and go easy until warm.
However, before I got the rotary my driving pattern with a piston engine was the same. I am quite sure that the piston engine did not suffer such a reduction in MPG because of the idle periods.
Does anyone know if the Rotary is more prone to gas guzzling at idle than a regular piston engine ?? Can't solve the problem I know, just curious.

It definitely guzzle more gas when idling than moving around. I'm getting quite good mileage now about 450 km full tank and I never idle, only the first 30 seconds warm up then take it easy under 4000 rpm. Shortest trip I take is around 12km with mixed driving habits but then again I lived in tropical weather.

When I drive to save fuel, I keep the RPMS below 3,750. The secondary intake ports open at 3,750 RPM (6 speed) and I construe that once those secondary ports open, the engine will start injecting more fuel. When I cruise on the highway I will set the cruise control at a speed that will keep the RPMS at ~ 3,600 RPMS.

I just got done doing my first trial mileage test with my mid-pipe installed:
22.5mpg!
(10-15 city, 85-90 hwy.)
Keeping revs low without lugging and only redlining about 5 times to pass. Warm-up times varied, but I made sure to accelerate at a rate that would piss off grandma. My best in the summer was 23.6 all interstate. I can't wait till it warms up and we switch back to a summer grade fuel mix! 25 mpgs Here I come!

Oh I forgot to mention I also have a gutted airbox (1st MAF screen removed) with a K&N cone filter mounted inside. I use Royal Purple 5-30 and Premix with Lucas Oil UCL (Upper Cylinder Lube).

Hi rx8wannahave and others - you get 19 mpg !!!!!! I would die for this, my average is 14mpg with many weeks at 6 - 10 mpg (US Gals).

6-10mpg Wahhhhhhh

I don’t see how you could get that even by trashing it like your life depended on it. Either you have a problem 8 or something in your driving habits aint helping your situation out.


I agree, while idling fuel is consumed and no miles clocked up, I do occasionally let her idles for 5-10 mins, but mostly do as you suggest, get on the road and go easy until warm.

Well when you idle the car for 10 minutes a day, you WILL get poor mileage.

A HA!

What he said, and it sounds like you do it for up to 20 minutes sometimes. That my friend, is what is really hurting you.

I’m in FL so our temp’s don’t get too low but regardless you shouldn’t have to heat her up for 5-10 minutes every day.

What I normally do in the morning is let it idle for about 30sec and then go. You warm up the engine faster by driving it but like already stated do not push the 8 when cold (or any car really). When the 8 is cold keep the rev’s under 4K max and if possible under 3.5K.

Oh and yes, my lifetime average has been just over 19 mpg in city driving (max 20.5 minimum 18.6mpg). I don’t hit a lot of traffic but my drive is not traffic free either. I don’t drive like a grandma but I’m not hitting 9K after each red light. I have a base 6spd fyi.

BALANCE is the key to have fun and maintain decent fuel economy. Also, like stated keep it at about 3.6K on the highway and that should help things out also.

I hope the best…try what we say and report back.

When I drive to save fuel, I keep the RPMS below 3,750. The secondary intake ports open at 3,750 RPM (6 speed) and I construe that once those secondary ports open, the engine will start injecting more fuel. When I cruise on the highway I will set the cruise control at a speed that will keep the RPMS at ~ 3,600 RPMS.

If you're cruising, then you're in closed loop mode. The ECU will determine the amount of fuel to inject based on the O2 readings. Whether it uses one or two injectors is irrelevant, the amount of fuel is the same. So there's no significant fuel efficiency differences at just under 3750 vs just over it. The only difference is that higher speed = more drag which results in higher fuel consumption.

For everyone telling him to redline it, remember he just got the car and is still in his break-in period. Take it easy for the first 600 miles and then let it unwind. Think of it as foreplay. :)

I am getting the distinct feeling that something might be wrong with my motor, less than 6 - 10 MPG is just ridiculous, and on a long trip 19 mpg was the most I ever got.
One thing I should mention about my warm ups, most of the time the temp gauge needle has hardly moved (Note most mornings here are 10 - 20F even in my garage), and I know the motor is not fully warmed because the revs are limited - so I don't think I am idling for and excessive amount of time.
With all that said I stilll love the lively performance of the RX8 and did not get the car for fuel economy.
Does anyone know if the repair shop can test for something that would lead to high fuel consumption? It's due for a service in a couple of weeks any advice on what to ask them to look for will be appreciated - Thanks.

they can run many tests for operation status and fuel consumption but you will have to leave your car with them for many days and they might make you pay for the diagnostic work.

tell us how you calculate your mpg.

If you're cruising, then you're in closed loop mode. The ECU will determine the amount of fuel to inject based on the O2 readings. Whether it uses one or two injectors is irrelevant, the amount of fuel is the same. So there's no significant fuel efficiency differences at just under 3750 vs just over it. The only difference is that higher speed = more drag which results in higher fuel consumption.

For everyone telling him to redline it, remember he just got the car and is still in his break-in period. Take it easy for the first 600 miles and then let it unwind. Think of it as foreplay. :)

I keep hearig about this closed loop and open loop but still had no idea how it works, should I just search or can you just share some summary of what it is?

Anyway there are two beliefs regarding break-in, one is baby it and the other is thrash it.

The ECU will determine the amount of fuel to inject based on the O2 readings. Whether it uses one or two injectors is irrelevant, the amount of fuel is the same. So there's no significant fuel efficiency differences at just under 3750 vs just over it.

Really....has this been proven or who said this works this way? I would like more information on this also.

Foamy, have the car checked out but again I just don't think you need to leave your car idle for such a long time in the morning. You will warm it up faster by driving it. 1 minute tops should be enough.

Hi Zoom44 - in answer to your question on how I calculate mpg;
Typically I let my fuel run down to about 1/4 full, then fill it right up, noting the amount (11 gals usually) and the odometer reading. Then drive the car until again I get to about 1/4 full. Note the odometer and fill right up again. The miles driven divided by the amount of fuel required to fill up is the mpg for this cycle. I have done this at every fill up since new (Sept 04) and I have it on a spread sheet. (Would attach it if I new how ?).
RX8wannahave - If I limit idle to one minute I would be in trouble as the car is not warm enough.
I know this because when I push the gas the car speed is slow and there is that strange "woomping" sound from the engine and it goes slowly because of the RPM limiter at low engine temp- Whamm some one rear ends me.

Odd^ I have given 0 warm-up time before, but kept the revs under 2.7k-3k and slowly accelerate with no engine sounds or ECU interference.

My warmup is always just until the idle is down to 1500 RPM and then I stay below 4000 RPM until the temp is up and don't thrash it until it is fully warm. I average a bit over 17 US MPG in mixed Canadian winter driving.
I have not had drivability issues even when cold other that the shifting issue.

RX8wannahave - If I limit idle to one minute I would be in trouble as the car is not warm enough.
I know this because when I push the gas the car speed is slow and there is that strange "woomping" sound from the engine and it goes slowly because of the RPM limiter at low engine temp- Whamm some one rear ends me.

Hmmm, like stated once the RPM's hit 1.5K you should take off. At that point you shouldn't have any issue with the engine. Now, it will still keep you under certain RPM's but remember you shouldn't be revving high when the engine is cold anyway. Heck...once it's at operating temperatures you should still wait a bit longer before pushing it to higher rpm's.

I honestly don't have experience with negative temp's (0 in NY is the coldest I’ve felt) but it's gotten to 35 here before and I know it takes a bit longer before I start driving the 8 but again 5-10 minutes just sounds excessive to me.

Once your rpm's fall to 1.5K...take off. Try that and see what happens…and then let us know.

You know if there is an engine that needs an engine block heater, it's the rotary.

Really....has this been proven or who said this works this way? I would like more information on this also.

Well, by definition, closed loop means the ECU reads the signal from the O2 sensor and adjusts fuel to reach a target AFR. See http://www.autoshop101.com/forms/h44.pdf for good background information.

So the question is whether the ECU is in closed loop or open loop when cruising. From the information posted by experts like Mazdamaniac, Rotarygod, Rasputin and others, as seen in threads like http://www.rx8club.com/showthread.php?t=53406 and http://www.rx8club.com/showthread.php?t=64509 it appears that with the coolant temp > 130F, throttle load <35%, engine RPMs < 5500 and constant speed, the ECU will be closed loop mode. In fact, running with cruise control on is the ideal condition for closed loop operation.

I'm sure someone with a CAN bus scanning tool could verify this.

The warm up time had puzzled me for a long time. I assumed that I was supposed to do what the dealer said and let her warm up for 2-3 min before leaving. But I soon got really tired of this and most people on here seem to agree to the 1 minute or less warm up time. I wanted to see what the dealer had to say again and after clarifying a simple question many times the guy said, "No, no warm up time is necessary, as long as it is not shut off cold. He really knew the part about shutting it off cold but not the part about the warm up. So, in order for better fuel mileage and a feeling of being "safe" I'm gonna let her warm up for about a minute or less. This works out well too because it's enough time to put the seat belt on, find a good song on the ipod, then throw it in gear.

It might be an interesting idea to call other dealers and see what their opinions are...

My typical 8 day goes like this. I let my 8 warm up for ~5 minutes before I leave for work in the morning. When I leave my house, I drive about 3 blocks before I have to enter the highway. At that point, I need all the power I can get usually. I typically redline it twice at that point. Between the 5 minute idle and a couple of redlines, I still get around 19 mpg all city.

Well, by definition, closed loop means the ECU reads the signal from the O2 sensor and adjusts fuel to reach a target AFR. See http://www.autoshop101.com/forms/h44.pdf for good background information.

So the question is whether the ECU is in closed loop or open loop when cruising. From the information posted by experts like Mazdamaniac, Rotarygod, Rasputin and others, as seen in threads like http://www.rx8club.com/showthread.php?t=53406 and http://www.rx8club.com/showthread.php?t=64509 it appears that with the coolant temp > 130F, throttle load <35%, engine RPMs < 5500 and constant speed, the ECU will be closed loop mode. In fact, running with cruise control on is the ideal condition for closed loop operation.

I'm sure someone with a CAN bus scanning tool could verify this.
125F to be exact :worship:
open loop condition when engines cold, hard accel, wot, & decel

Hi Zoom44 - in answer to your question on how I calculate mpg;
Typically I let my fuel run down to about 1/4 full, then fill it right up, noting the amount (11 gals usually) and the odometer reading. Then drive the car until again I get to about 1/4 full. Note the odometer and fill right up again. The miles driven divided by the amount of fuel required to fill up is the mpg for this cycle. I have done this at every fill up since new (Sept 04) and I have it on a spread sheet. (Would attach it if I new how ?).
RX8wannahave - If I limit idle to one minute I would be in trouble as the car is not warm enough.
I know this because when I push the gas the car speed is slow and there is that strange "woomping" sound from the engine and it goes slowly because of the RPM limiter at low engine temp- Whamm some one rear ends me.


good - we have some people in the past who did not calculate properly. they would run it down to the ligth came on or whatever fill up and then use gallons for an entire tank instead of the amount of the fill. so im glad you have that straight

the rest of that- "woomping sound" car wont speed up so people rear end you... thats really somethign i cant fathom. the rpm limiter when cold is about 6- 65 k rpm. that is plenty of rpm to get you to what ever speed you need. i seem to hav emissed any previous mention of womping- can you go over that again?

im thinking you have a clogged cat btw. no air out =no power= bad gas mileage.

on decel- the car actually cuts fuel injection. afr goes to like 20!

Hi rx8wannahave and others - you get 19 mpg !!!!!! I would die for this, my average is 14mpg with many weeks at 6 - 10 mpg (US Gals).
Measure by filling up and noting miles at every fill up since new.
I got my new AT in Oct 2004, love it to bits, but the fuel economy often tests my love for it, mainly because I have to stop for gas every 150 mils or so.
Do the experts out there think I might have an engine problem, I got most Flash updates (I think), I live in the cold NE USA so have to remote start my RX8 for 5 minutes twice a day.
For those that tell me to do a search, I have and not got much relevant information - re-borne threads are not all bad IMHO

This is the only real problem with this can for me. Performance is good, looks are great, ride is great but MPG is bad and Mazda is doing nothing to fix it.

I get 11 to 12mpg city driving very conservatively, Highway is around 17mpg, other RXs are getting much better why? I'm bringing the car in next week but from all I've read the dealer will not do much if a flash and spark plug change don't fix it. They will write it off as driving style and dismiss me, which is bull.

I read all the posts before buying and expect 15mpg which I thought was bad but at least I bought it with this lower expectation, then I get 11 to 12mpg. I have only read of two people on this board who had their mpg increased after a visit to the dealer so I am not optimistic. I have read of dozens who have been turned away by Mazda and told to live with it.

Now lets look what Mazda's in action has cost them, one potentially loyal customer disgruntled and feeling abandoned. Every person that this individuals talks to about his RX is warned about the dismal fuel mileage and lack of resolution by Mazda, those people walk away from the RX after hearing of the problems and the word spreads. Mazda's RX sales are down and we wonder why.

I know this is a recurring complaint but it really pisses me off that Mazda know there is a problem but has no resolution.

We shouldn't use oil consumption on piston engine as a benchmark for one on rotary engine.

Hi Zoom44 - the "woomping sound" and speed limitation is bit like throttle is open but fuel and air to the engine is being strangled, at least that's what goes through my mind when it happens. RPM's are definitely limited to much lower than the 6k you mention, lucky to get above 2.5k.
This sympton goes away very quickly, maybe 1/4 mile driving and it only happens when it is really cold < 20F.
I called a new Mazda place today and they are going to look over my car next week, I mentioned possible clogged Cat' they said most unlikely if I did not have a check engine light and performance would be very poor at any temperature.
Will let you know what they find (If anything)

At the risk of beating this subject to death - does anyone have a reliable technical explanation why the RX8 rotary engine gets such low mpg compared to a "Similar" piston powered sports car.
Also, to be specific why at idle does the fuel consumption appears to be significantly higher than a piston engine at idle, is this true ?? it certainly seems to a factor.

i just got the car and i get about 14.5 mpg. that jusk suck too