Hi Everyone,

I have a new (2010) RX8 manual that I have put 1500 miles on in the first five weeks. I am breaking it in and taking things easy but I have a question for the group.

I feel that I might not be shifting into the next higher gear soon enough. I am in no way "winding it out" but this car seems to have the ability to cover a very wide range of RPM's in each gear. I am getting around 16 mpg and I feel like I am not driving aggressively. I read about people getting higher mileage and I thought maybe I am in the wrong gear all day long without knowing it?

I get out of first really quickly (seems like around 8-12 miles per hour
I carry second up to around 20-25
Third goes up to some very fast speed but I usually shift around 30-35 and I stay in fourth gear around town when the limit is 35 MPH.
Should I go 35 in fifth gear? Is this safe for the car and will I get better mileage if I us fifth for in town cursing at 35?

Thank you for your thoughts,
Yogi

 

You are going to get a bunch of different responses for this question, but it really depends on your car and how you plan on driving your car. Some people on these forums abide by the "book" value of shifting on a normal daily drive which is roughly 45mph max on 4th gear if i remember correctly. So if you are going by this value, then no, stay in forth.

I personally like to drive on the "highest maintainable" gear. So if i shift to 5th gear and the car sounds ok, then i stay there. If the car sounds like its gasping for air, then i downshift and stay there.

There are a lot of factors that come to decide exactly when to shift, but the best advice is to really "listen" to the car. Just by listening you can really grow to understand the car and know when it likes to be shifted and exactly when it is comfortable.

16mph is honestly average for the car.

 

The Owner's Manual, as with most vehicles, cites the shift range for optimal fuel efficiency and also for cruising acceleration.

However most of us like to utilize the rotary in a more 'spirited' fashion and therefore tend to hold it in a particular gear longer than 'by the book.' The rotary is so smooth at higher rev's that I sometimes forget to upshift to the next gear.

Higher rev's also help to keep the carbon deposits at bay, but of course at the expense of fuel economy. But then, even if "granny shifted' the mpg isn't very good.

I average 18 mpg in spirited, lighter traffic, 60/40 highway/byway driving.

 

I found there barely difference between driving hard or normally.

 

Agreed, I'm starting to come to the same conclusion...


Manuf. suggests keeping it between 3k and 4k when cruzing. Regardless of what gear your in and or how fast you are going.

 

Wow I feel much less crazy now for thinking the same thing.

 

nope.
a lot of them are like that. if you think about throttle position and the amount of gas consumption the engine is using at the 3-4 k range. it should technically consume the same amt regardless of gear.


I SAY SHIFT WHEN YOU HEAR A BEAP!!!!!!

 

+1 after its broke in it tells you when to shift. BEEP!

 

Highest gear possible without lugging the engine

 

~9024 RPMs.

 

yepper skipper

 

try 9100rpm

 

Amen, it is really that simple. 2000\3000rpm is an acceptable rpm range mpg wise.

35Mph on a flat road means 5th or 6th gear with just a bit of gas =)

 

that's lug city in 6th.

I do the following when cruising around town

1st to 15mph
2nd to 25mph
3rd to 35mph
4th to 45mph
then 6th above that

When overtaking if 60mph+ 3rd otherwise 2nd.

5th gear hardly ever gets used in my car. It just seems kind of pointless, according to my gas tracker app I manage 17-18mpg mixed. Never driven down the freeway for a whole tank to get a good highway rating

 

That's why you manage to get 18mpg and i often see 24 mpg

 

call me when you make 26/27 :P

 

By the book (very conservative/fuel efficient):

 

Lol if u look at the cruise speed and next set of gears used, they look alike. Did they just simply made it up?

 

overdrive

 

Yeah, but to be perfectly honest, with the possible execption of 1st gear(I like to take it easy on 1st), I would normally exceed these by 10-12mph.

I just can't sit in 4th at all gear until at least over ~38-40mph.
On a normal commute(non-freeway and not on my normal let's clean some carbon run).........Seems like this is the point where I am attempting to have a conversation with the person in front of me................speed up, slow down, or get the "F*&^" outta my way!

 

I shift when my shift light blinks, I have it set at 3250rpms on the dashhawk. Which is very close to the Owners manual shiftpoints I discovered.

 

I'd like to see your 24mpg in mixed driving. The way the freeways are around my area it might as well just be 18mpg city with all the stopping and starting

 

I'm seeing 14 right now after my rebuild, I have fouled plugs and a bad 02 sensor as well. I shift between 3 and 4 usually.

 

The rotary is smooth and quiet so wind it out/hold gears for as long as u can. It likes it.

And how the hell is anyone getting 24 mpg?! The best I could do was 21 and that was during the break-in where I never exceeded 4500!

 

I live in Rome so no freeways at all and in pure city driving i get around 21mpg with a shorter final gear.