Well explained, B.L.E.
I acquiesce and thank you for setting me right. A lesson learned through a corrected error is one learned for all time.
TSM
I can’t buy into the hammer it like you stole it and the fuel mileage will be better theory. After many years of playing around with the message center on my Lincolns (which I have found to be deadly accurate) and conditioning myself to certain driving habits I agree with keith.
From a dead stop and pedal down there’s no way on Earth I’m getting 10 MPG and as keith mentioned; it’s more like 2. If my foot is on the pedal with the pretense that an egg separates the two then I can eke out 8 to 10 on acceleration.
That 0 to 25 MPH interval is the one where mileage goes way downhill; progressively getting better the closer to 25 MPH the needle gets.
What helps me more than anything with mileage is trying to always think ahead; coasting to stops, easing up a bit to catch a light going green, avoiding pain in the neck heavily traveled streets, and so on.
You can’t buy into it OK4450? You mean all this time I’ve been doing it wrong? But… but… punching it is so much FUN!
Seriously, I know for a fact that when I drive aggressively my mileage drops. It has in every vehicle I’ve ever owned. I track my mileage carefully, always have, and I speak the truth.
Perhaps the OP’s racecars get better mileage when driven aggressively, I can’t speak to that. But I’ve owned cars for over 45 years and they’ve all gotten better mileage when driven conservatively. That’s good enough evidence for me.
@ok, perhaps you missed the point about using a heavy foot on the throttle AND shifting out of low gears early. I know you can’t do that with an automatic since your foot is also telling the transmission to delay shifting to redline. But try that in one of your favorite Lincolns with a manual transmission and see what happens.
I think there might be exceptions. On an econobox with a one liter engine and traction control, you can pretty much floor it and still get 29 MPG. It’s only when your car has extra power to spare (which applies to most cars) that throttle position has a profound effect on fuel economy. The guy riding a 250cc motorcycle can pretty much ride with an open throttle without experiencing a noticeable drop in fuel economy.
You should floor it from a stop, especially if there is another red light 1000 feet ahead. Thats how people here drive.
1000 feet? You have long distances between lights. Around here, the race is to jockey for position at the light a few hundred feet ahead. Gotta be first in line, ya know.
Yesterday, I was in the turning lane, to make a left turn
I was moving at a good clip, but somebody suddenly cut in front of me, because I wasn’t moving fast enough for them
The funny thing was, I saw them pull in front of the store. They were in such a f . . . . . . g hurry, that they let the engine idle, and they were on the phone. They had “an advantage” over me, but they negated it, by letting the car idle and talking on the phone. When I got out of the store, that jerk was still on the phone in the car
His aggressive behaviour didn’t amount to much, in the end.
It was an Important Call, and all his calls are a Important enough to force everyone to get out of his Very Important way. Although a VIP like him should be able to talk while he drives, even though it is illegal in Cali for everyone else.
@Whitey, I’d think that a large engine running at closed throttle would require more energy as more air has to be sucked through the throttle. The large 3.7l V6 from Nissan runs at full throttle most of the time-it uses variable valve lift to control its air intake.
When you throw variable timing into the mix, it changes a lot, but not in that direction. With the throttle mostly closed, the computer thinks you don’t need extra power, so the valve timing would be in economy mode. With the throttle open wider, the timing would shift to power mode. @bscar has a VTEC engine, so he can probably confirm this. Why would an engine with a mostly closed throttle need more air than an open throttle? The throttle plate position controls air flow.
I think the Toyota Prius actually uses variable valve timing to control the power of the engine instead of closing the throttle. The engine still has a throttle valve but it only closes for the most low power situations where the intake valve would still be open when ignition occurred if it was done by valve timing.
The engine is largely throttled by extremely late intake valve closing, allowing the piston to blow the excess charge back into the intake manifold.
Some call this the Atkinson cycle engine.
I believe the Toyota VVTi goes Atkinson at low power. When cold, the engine runs normal Otto cycle because the high intake vacuum resulting from a closed throttle helps to vaporize fuel.
Throttling an engine by variable valve timing goes all the way back to 1849 when George Henry Corliss invented the Corliss steam engine that throttled by closing the intake valves earlier for lower power.
Closed throttle requires more ENERGY, not AIR. Variable valve timing has been around for a while, variable lift is a new technology that’s used in a handful of engines. Variable lift takes over the job of the traditional throttle as it creates minimal manifold vacuum
@Whitey "The guy riding a 250cc motorcycle can pretty much ride with an open throttle without experiencing a noticeable drop in fuel economy."
I’m that guy, well the Ninja 300 is basically the Ninja 250 with the stroke increased from 41mm to 49 mm giving it 296 cc.
Yes you can kill the fuel economy of a small bike. I get around 72-76 mpg. Take this bike on the freeway and pass all the traffic using the left lane and you can expect 50-55 mpg.
Small motorcycles accelerate effortlessly because they are light but struggle to cruise at high speeds because motorcycles have a lot of wind drag. The real key to getting good fuel economy on a small bike is to find roads that have 45-55 mph speed limits. It makes little difference how quickly you accelerate to that cruising speed. Avoiding high peak speeds gives more results.
For example, lets consider a 5 mile trip where the driver slowly milks the vehicle up to a 60 mph cruise speed using an entire two minutes to reach that speed. At that rate of acceleration, the entire first mile of the trip will be spent accelerating up to the 60 mile per hour cruise speed. This means it takes 6 minutes to travel that 5 miles for an average speed of 50 mph.
Suppose that instead, I make that same trip in 6 minutes by accelerating to 52 mph quickly and then cruising at 52 mph instead of 60 mph. I think that on a 250 cc bike, the latter will be a far more efficient way to average 50 mph on that 5 mile trip.
Yep, I used to get better fuel economy on my 750 Honda Shadow in stop-and-go traffic than on the highway, but my Nighthawk 750 is a different animal, and with the fairing, it’s the opposite.
The only gas engines I know of without a throttle are from BMW. The rest combine variable valve timing with a throttle (now electronically controlled).
Live and learn. The 3.7 l Nissan engine has a system similar to BMW’s, no throttle plate:
http://www.nissan-global.com/EN/NEWS/2007/_STORY/070329-01-e.html
Toyota has a similar system on one of their 4 cylinder engines, only one on sale here is in a Lotus.
All you guys with motorcycles . . . You’ve never lived until you had an Italian MoPed. I used to get a top speed of about 32 mph. In the winter when I put the windshield on, it cut back to about 26 top speed. That’s significan wind drag. I don’t know what the mileage was though since I had to peddle it quite a bit when it wouldn’t start. The Sheriff made me promise to sell it which I did.
I remember those old mopeds that had peddles. One of my elementary school teachers had one of those in the late 1970s and early 1980s.
“I remember those old mopeds that had peddles. One of my elementary school teachers had one of those in the late 1970s and early 1980s.”
Did she peddle herself all over town in order to earn more money, or did she just pedal herself around the town?
;-))