jblaze4lif

55mph, 65 mpg, 70 mph .... hmmm???

DanielNC06

i would think it would be the lowest speed in the highest gear...I've heard the best mpg is around 45ish mph

jblaze4lif

its gotta be where the engine is most efficient ....

Sciontistical_One

iTrader: (2)

heck, I can cruise at 40 in 5th gear, but I don't know if that's the most efficient.

locondcoco

i recently did about a 200 mile trip cruised at 65. i did not see better mpg than when i've done trips cruised at 75 and 80. comparable conditions temp and weight wise.

Supercharge_returns

I got better MPG cruising at 55MPH to cleveland, it was like a 4 hour drive got like 300MPT. Cruising back at 75MPH I got like around 220MPT but it all depends on how you drive it IMO.

olo_olo

@ 0 rpm

tCeeder

iTrader: (1)

i'd say in 5th gear around 45-55, if you're under 3k rpm in 5th you should be sipping fuel.

heck if you shift before 3k rpm in all gears, you should be getting pretty good gas mileage as long as its not constant stop and go.

scion_thC

i think the owners manual says shift at 3k. with the scanguage after 3k in fifth the mpg goes down. If you really want to know get a scanguage II. i find that i drive better ( gpm wise) with the scanguage because you can see real time gpm. and its kind fun

jblaze4lif

I think the slowest I can go on parkway might be 60 lol. Ill have to try it, one week drive to work going 60mph next week 70 mph next week 75 mph.

Gas is sooo much this kinda stuff def important lol.

yellowxhoodie

iTrader: (16)

the lower the rpms the better gas mileage your getting.
i usually shift at 3K.
and try not get above it when im in 5th gear.
3K in 5th is about 70mph.

draxcaliber

wow...220 mpg and 300 mpg...do you mean 220 and 300 miles per tank?

draxcaliber

according to motortrend, the most fuel efficient way to drive is wide-open throttle short shifting, which i really don't believe.

but ideally, you want to drive and shift in an efficient manner for the car. just because you shift early and drive slow does not mean you are driving efficiently for good MPG, because the huge load on the engine and the stress on the transmission will really hurt the engine in the long run. this is called "lugging the engine".

under most conditions, you want the engine speed to be about 2000 rpms, usually upshifting at about 3000 rpms, but that isn't always true, for instance, accelerating downhill, the pull of gravity means i can be at 1500 rpms, and perfectly fine because there isn't much strain on the drivetrain. however, if i am going uphill, i would downshift and be around atleast 2500 rpms but probably toward 3000 to 3500 rpms.

now driving slowly does not gaurentee high MPG. i started getting much better mpg by reducing the number of times i come to a complete stop. for instance, approaching a stop light, i downshift and engine brake while approaching the intersection, the momentum of the car keeps the engine turning, but because there is no throttle input, the ECU cuts fuel to the engine, versus coasting in neutral, the ECU has to send fuel to the engine to keep it idling. but back to not completely stopping, i'll roll towards a redlight engine braking, and hopefully the light turns green before i get there. this saves gas because one of the most fuel consuming manuevers in a car is moving away from a complete stop.

also, keep an eye on what is going around down the road. don't waste gas accelerating if you can see your going to have to slow down or stop for something in plain sight down the road. don't waste gas speeding up to pass a car, if you can see you'll just have to slowdown because of the car ahead of that.

using these proactive and conservative driving practices, my best MPG average was 33 mpg, woulda been better, but every not and again, i need to feed alittle speed to my ride. now i'm supercharged, and it has gone down a bit, to like 29 mpg when i was breaking it in, trying not to boost often while breaking in the supercharger, and now i'm at 26 mpg because that supercharger is a bad influence. gets me drunk with boost power.

SquallLHeart

i've gotten 400+ miles from one tank before...

driving like grandma, drafting behind a semi on a long trip.
(was probably at 55pmh most of the way)

arbnpx

I'm sort of smiling because today on the drive home, I was paying attention to the ScanGauge II in certain parts of the drive home.

The one indicator that I have up most of the time is Gallons Per Hour (GPH). This shows the general fuel consumption rate of the engine, ignoring vehicle speed. A few things I noticed:

30 MPH driving: 1.00 to 1.30 GPH
65 MPH driving: 1.80 to 2.10 GPH
Idling when cold (coolant under 70 F): 0.89 GPH
Idling when warm (coolant at 180 F to 190 F): 0.25 GPH
Coasting down a hill: 0.00 GPH
Engine unloaded (clutch fully depressed), revving down from high rev to idle: 0.00 GPH
Speeding up from a full stop (normally): about 2.00 GPH to 3.50 GPH
Taking off from a full stop (hard acceleration): over 4.00 GPH

Climbing up a hill requires more engine load, and therefore more fuel consumption; going the same speed, you'll see the GPH reading climb upward a little bit higher than it would on a level road surface.

Coasting down a hill requires less engine load, and therefore less fuel consumption; going the same speed, you'll see the GPH reading descend lower than it would on level travel. If you lay off the throttle and slow down a little (or if the hill is steep enough to maintain the same speed or go faster), you'll see the GPH reading go to 0.00, meaning that you're not burning any fuel (the momentum of the car is enough to keep the engine turning via the drivetrain).

Engine braking: 0.00 GPH. This confirms it: engine braking GOOD! So instead of standing on the clutch while coasting from 40 MPH to 20 MPH, use engine braking. Instead of the engine idling (and consuming 0.25 GPH), the engine will be turned by the momentum of the car turning the drivetrain.

Some basic guidelines to take out of this:

- Don't accelerate overly hard; this wastes fuel
- Try to maintain a relatively steady speed, and accelerate gently
- Try to plan a route with as few stop points as possible, since rolling from a full stop consumes more fuel than being able to drive straight through on another route

I also think I saw that driving 70 or 75 consumes more fuel than driving 60 or 65. So take it easy, leadfoot.

If you take your current speed in miles per gallon, and divide it by the gallons per hour, you get miles per gallon. I believe this is how the ScanGauge calculates the real-time MPG reading. For real-time fuel consumption, I found the GPH display more intuitive because it doesn't "dance around" as much as the realtime MPG (at 0.00 GPH, the MPG reading says "9999", while at a high GPH, the MPG reading says something really low like "7.4").

Luke88

So my friend who goes to an automotive school (ITU) has told me that engine braking has negative effects on the life of the engine. Is this true ?

sciontc_mich

probably not the engine, but the transmission/clutch would go through more usage, and over time that leads to less life.

I've always heard, use the brakes, they're cheaper than a transmission

AAG

iTrader: (1)

Engine braking won't effect the engine (unless you over-rev) but it will wear you clutch faster.

If the brakes were a little better I wouldn't do it at all. I'm hoping once some SS lines & upgraded pads come out, it will fix the issue.

sciontc_mich

i've recommended porterfield's r4-s pads before. That would make a HUGE difference in performance (in a good way)

you also have to think about tires, because that's also helping you slow down quick (grip).

arbnpx

for medium to hard stopping, definitely use the brakes, but coasting in gear a little longer, or downshifting from 5 to 4 and coasting along with braking would result in a bit more of that time when the engine is in the "cutoff mode". Like anything else, don't overdo it.