KYLiquid

i live in FL, anytime is over 80*F or really humid I run the AC on recirculate fan setting #3. So thats about April to August that I use the AC when I drive. I shift at 4k most of the time driving in the city, and cruise in whatever gear I need to so im always around 4k rpm so I have power......i rarely use 6th unless im on the freeway, I use 93 octane shell/chevron ONLY and run a fuel system cleaner every tank and a double dose every oil change. I also pre mix 2cyle syn oil in with my gas, at a 400:1 ratio.

On top of all that I redline gears 1, 2 and 3 all at least once everytime I drive the car, change my oil/filter ever 3k with castrol GTX and change my spark plugs ever 10k miles along with cleaning my K/N drop-in filter. My car runs well, its pretty peppy and I get 18-20 mph city. I drive 250 city miles PER WEEK and rarely use the highway. Most of the time I get 19.5-20 mpg, occasionaly I get 18-19, and I have never gotten less than 17mpg......so thats where I get 18-20mpg from.....

cheers

KYLiquid

down shifting is only using gas when you rev-match.

whenever you coast in gear (engine braking) you dont use any gas.....so coming up to a stop, if you shift into neutral and use the brakes you use the gas to idle the engine, if you just let off the gas and then put it in neutral when you stop you got that distance for 'free'

I only downshift at the track, but I do let off the gas and coast in gear up to stoplights, using the brakes but leaving the car in gear till I just about come to a stop.

Elara

Erm. Gee. Thanks. Really. Have you checked out any of the other threads about this yet on here? There's only a few thousand.

Are you SURE you got 29mpg? People doubt me when I tell them I went 310 miles on one tank (13.5 gal before someone starts in the "YOU CAN'T MEASURE BY TANK" junk)before the light went on, once, and that wasn't anywhere close to 29 mpg. More like 24mpg. I'm not trying to call you out, by 29mpg? You'd be getting what, something like 400 miles on a tank? I've never heard of anyone doing that before.

SlayerRX8

Yeah, I smell BS.

zoom44

hmm well i hav emade over 24. recently brilo made 27mpg on a trip. 29 is stretchign credulity tho

Glyphon

you and your flat state
although, i'm not too far off that. 17-20, with a 50/50 mix of driving...although i don't know if those highway miles should really count as highway miles, as most of those are in stop and go gridlock.

Low Fly'n 8

Always 20+ mpg regardless, but never more than 22 even on highway trips. It's hard to run 72 mph around here without getting run over by an SUV or pickup.

37,000 Miles
12/03 Build Date
Only 93 octane Ammoco Ultimate
Castrol GTX every 3000 miles
Latest "hot" plugs from mazda
Racing Beat Exhaust
Green Drop in Filter
245/40/18 BFG KDW 2's

mkztg

Ok, I give up. can someone explain rev-match to me.. please

Thanks

KYLiquid

when you downshift a car (say go from 3rd to 2nd gear) if you just put the clutch in, change the gear, and let the clutch out, the engine will be forced to quickly speed up to match the speed of the rest of the drivetrain, so when you rev-match, you 'blip' the throttle so that it speeds the engine up, that way when you downshift and let the clutch out, the engine is already at the speed it needs to be at.

Also in older cars, before manual transmission had syncros, you would have to match the engine rpms to the gear you want to go in, so that everything is spining the same speed.....

"REV-MATCHING:
When taking off from a stop and then going up through the gears, steps 1,2,6,7 above are the normal shifting method for each gear change. The synchro-mesh are more than enough to control the intermediate shaft speed. The engine will passively rev-match itself because it slows down naturally and this is appropriate when shifting up.

When down shifting, the engine needs to spin faster as it engages the new gear. This can be achieved by 'blipping' the throttle as the transmission passes through neutral. If the engine isn't manually sped up by the driver, it will be sped up by the driveline when the clutch is re-engaged. This can be OK for normal street driving, but if the car is cornering near the limit this can upset the suspension and the tire adhesion.

The synchromesh are usually adequate intermediate shaft control when down shifting one or two gears. Aggressive downshifts (like a 5 - 2 shift from high speed) can benefit by using double-clutch shifting to assist the synchro's. Shifting into first gear in a hard corner is nearly impossible without double-clutching (this is useful for those really tight hairpins, especially if they exit uphill). "


hope that helps

UFGator12

Today, was my best tank ever! 17.2 mpg! That's amazing! It was about 90% city. Normally, I do all city and I get 15 mpg. I was at about 240 miles on the tank. Normally i get about 208. Something around there.

Nemesis8

iTrader: (3)

I got tanked last night at the Green Lantern

Old Rotor

When I had the patience once, and the chance to drive in the slow lane with the trucks I did get 29.5mpg. It was doing 55-60mph for two plus hours. It is very hard! I got 27.5mpg twice doing 65mph. I use the cruz.....and have AT.

Revolver

About the only startling thing in this thread is that people still think 32psi is right because the manufacturer's placard says so.

Personally, I use 36-38psi for urban driving and boost it to 40psi when on a long freeway trip.

If anything, lowering the psi will increase fuel consumption.

As for the fuel tip - gee, if I don't rev the car I'll save fuel?? Really?? Thanks. I NEVER would have figured that out on my own.

maisis00

I calculated yesterday when filled up and I was at like 285miles on 14.5gals. It was like 19.8 ml/gal. I also probably ate up a couple of quarter tanks in displays that are known in these parts as "exhibition of acceleration."

Aseras

doesnt matter how hard or softly aka granny I drive my rx8, always in the low 20's. Usually 21-23. Long trips where noone pisses me off, and I'm not in a rush and I keep my foot out of her, I've gotten 27.

40,000 miles since april 1 05. my lifetime mpg is 21.06

Octane doesn't matter either, I actually tend to get better mpg on 87, but it MUST be good QUALITY gas. If it fill up with the cheap no name crap, my car runs accordingly. It still get good MPG, but it's retarded feeling, it's not smooth and happy, it's clunky and slow.

Low Fly'n 8

I'm thinking 40 psi in the tires could wear the center tread section out prematurely, not to mention ride quality would have to comparable to that of a covered wagon, especially if you have aftermarket springs. I could be wrong, though.

Revolver

You're wrong.

Seriously, ride quality does suffer a little, which is why I reserve 40 for long trips on decent freeway.

However, wear is even.

90% of motorists don't have enough air in their tyres (this from a number of experienced defensive drive instructors, all of whom have advised 30-32psi is too low for a family sedan let alone a performance car with low profile rubber).

swerver

well, er, I'm brand new here, just bought a few days ago. And while its difficult to guage how much gas the dealer actually put in the car and other intangibles, it looks like I got about 16mpg on my first tank (and I was driving like a grand-ma!!!.......haven't even put the car over 6K rpm yet)............ugh...........................

SilverEIGHT

I decided to granny drive for a full tank of gas to see what I could squeeze out of mine. I stayed below 3500 RPM (except for a few minor falls off the wagon) and moved as slow as possible trying not to press the accelerator any further or faster than required to stay up with traffic. Man I pissed off a lot of pick-up trucks. If I had gone any slower, I would have had to speed up to slow down.

I filled up today and got 17.3 MPG. That's approximately 70% city and 30% Interstate. I normally get in the 14-15 range if I'm lucky.

I don't think I can keep this up because I really miss beeping and listening to my RB exhaust. With the price of gas going through the roof, that gives me a little more incentive to poke my way to work.

LiL BenNy

what mph were you guys crusing at?

Butch Brown

21-23 mpg hilly country roads shift at 5 - 8 k. 1/3 throttle and wait for rpm's to peak when accelerating, coast downhills. 25,000 miles on 2004.

ALP22

72mph in 6th. That keeps the revs right around 3750, and the other intake port kicks in at 3800 (so I'm told). This routinely gets me about 22mpg on the highway. Its a 2005 GT running mid-grade gas (89) and with about 3k miles on the clock. Round the city, I get 16mpg typically.

Paul_in_DC

My best so far was 23 mpg... All highway, ~75 mph, flat terrain, cruise control, ~85 deg F ambient temperature, Shell 93. Typical around town is 17-18 mpg.

BlueSky

I think cruise control is a very crucial factor in getting good gas mileage.

Georgia8er

My last long trip in my 8 I got 24.4 mpg. Cruise control and 70-75 most of the way, some 80's. Normal driving in my area I get 21-23. I haven't had a tank under 20 since before the M flash. And yes my fuel economy seems to be improving as I get more miles on, even though it currently has only 13,000.