The (Don't Yawn!) Fuel Economy thread!

[IJ Reilly]

With the exception of traffic being really backed up or a really short off-ramp, why are you slowing down before the ramp?

Because that's what you're supposed to do? Even if you don't choose to obey the exit ramp speed limits, allowing the car to coast to a slower speed is a way to save fuel. If nobody is behind me, sometimes I coast for 500 feet or so. It becomes kind of a game to hit the top of the ramp at exactly the exit speed limit.

 

[yg17]

On the topic of clutches and shifting, how do you all shorten your time between 1st and 2nd when you're off the gas and shifting (where the gap in acceleration is most noticeable?)

I never realized the pause was such a big deal until yesterday I'm accelerating from a stop, and the schmuck behind me nearly plows into me before getting into the lane next to me, flipping me off, and speeding off. Or is this just a one-off scenario of a guy being a dick?

 

[crazytom]

I'm in a 1991 Geo Metro (manual). I average 43 mpg (US) combined. I've changed my way to work, travelling an extra mile, but using back roads, rolling through stop signs (not legal, I know....but it's in the country and I can see all directions for a country mile), and getting about 51 mpg. Yes, I coast A LOT; I entertain myself timing my speed so I'm going 5-10 mph when reaching a stop sign, it's pretty boring that last 100 ft or so.

The best I ever did was travelling 490 miles on one tank (about 9 gallons), I had a 25 mph tail wind and got 55 mpg on the highway.

 

[TEG]

I have a 1991 Ford Taurus Sedan. In January 2006, I was able to get 33 MPG from it while traveling between Dickinson, ND and Alexandria, MN. Usually I get 20 MPG in the city and 26 on the freeway at 75+. If I buy fuel in Oregon (were all fuel is E-10), at ARCO, or use Plus Gas in Iowa or Nebraska (also E-10) my mileage drops to 22 on the highway and 18 in the city.

I currently live in a town on a hill, whenever I have to travel down the hill, I coast the entire distance. It may not save me much, but when I lived in Flint, MI and had to travel 10 miles each way, 4 days a week, I was able to not get gas for 4 weeks, by simply shifting to neutral on hills and when approaching red lights.

TEG

 

[LumbermanSVO]

Because that's what you're supposed to do? Even if you don't choose to obey the exit ramp speed limits, allowing the car to coast to a slower speed is a way to save fuel. If nobody is behind me, sometimes I coast for 500 feet or so. It becomes kind of a game to hit the top of the ramp at exactly the exit speed limit.

Unless there is an immediate turn, a short ramp, traffic backed up, you are in a very heavy vehicle(large truck) or some other hazard you should be doing your slowing on the ramp, thats what they are there for. If you aren't slowing anyone down then fine, but if you are slowing traffic then all you are doing is slowing other people down and causing them to use more fuel.

BTW, I drove from Dallas to Albuquerque today and filled up when I got here. I did 66MPH most of the way only slowing for traffic, construction and other speed limit changes. The trailer was slid all the way back due to not having an easy to access/free scale to check my front axle. 13k of appliances in the trailer. I have 30 minutes of driving time left for my day when I got here.

734 miles on this tank, 668 of that was today
19.25 hours of idling on this tank
129.9 gallons burned
5.7 MPG
129.9 gallons @4.728 per gallon = $614.17 or $.84/mile

I have 620 miles to go tomorrow, mostly us and state highways. I have a free scale here to play with so I'll slide my trailer forward for better aerodynamics. I'm expecting 5.5 MPG tomorrow.

 

[r.j.s]

2005 New Jetta, 2.5L 5cyl.

I get 25 mpg in town, most speed limits are 30mph, and around 35 mpg on the highway doing about 75mph (tested in April, I drove from Central Texas to Baltimore) I got about 450 miles from my tank on that trip.

 

[IJ Reilly]

Unless there is an immediate turn, a short ramp, traffic backed up, you are in a very heavy vehicle(large truck) or some other hazard you should be doing your slowing on the ramp, thats what they are there for. If you aren't slowing anyone down then fine, but if you are slowing traffic then all you are doing is slowing other people down and causing them to use more fuel.

Did you read what I wrote? I guess not.

 

[StrawberryJam8]

Fuel crunch

The fuel hikes are getting on my nerves. Hope it doesnt keep going up anytime soon.

 

[LumbermanSVO]

Because that's what you're supposed to do?

This pretty much says that you believe you MUST ALWAYS slow down BEFORE the the ramp.

If nobody is behind me, sometimes I coast for 500 feet or so.

This implies that you just slow down even sooner if no one is around you.

Did you read what I wrote? I guess not.

I guess I was reading what you wrote and not what you meant.

 

[IJ Reilly]

I guess I was reading what you wrote and not what you meant.

Neither, really. Slowing down that so you don't hit an off-ramp at freeway speeds is correct and lawful. That's why they have slow lanes. I know most people hardly bother to observe speed limits, but they are still the law. Also, I was clear (I thought) that I don't make a habit of obstructing traffic. OTOH, if some nitwit thinks he's entitled to drive 80 in the right lane, he'll get no cooperation from me.

 

[iJohnHenry]

I think I have just proved my point.

All posts are about the individual.

If you are well-healed, well bless you.

But for the rest of us, we best consider other methods.

 

[Lord Blackadder]

734 miles on this tank, 668 of that was today
19.25 hours of idling on this tank
129.9 gallons burned
5.7 MPG
129.9 gallons @4.728 per gallon = $614.17 or $.84/mile

I have 620 miles to go tomorrow, mostly us and state highways. I have a free scale here to play with so I'll slide my trailer forward for better aerodynamics. I'm expecting 5.5 MPG tomorrow.

You know, I never knew what the fuel consumption of a Semi was...5.7mpg huh? Wow, I guess I figured it would be at little bit higher. What kind of fuel consumption does it have at idle?

 

[IJ Reilly]

What kind of fuel consumption does it have at idle?

0.0 MPG.

That was easy!

 

[Lord Blackadder]

0.0 MPG.

That was easy!

Ha, I was thinking more GPH than MPG...

 

[RITZFit]

On the topic of clutches and shifting, how do you all shorten your time between 1st and 2nd when you're off the gas and shifting (where the gap in acceleration is most noticeable?)

I never realized the pause was such a big deal until yesterday I'm accelerating from a stop, and the schmuck behind me nearly plows into me before getting into the lane next to me, flipping me off, and speeding off. Or is this just a one-off scenario of a guy being a dick?

you could redline 1st and powershift to second (your tranny prob wouldn't be long for this world if you kept that up that lol). People like that can just wait...the world doesn't revolve around them. I've had people throw up their hands at me because I didn't take off a quick as they wanted. because I drive a torqueless honda, theres nothing I can do, and Im definitely not going to destroy my car (especially when the engine is cold) for some impatient joe shmoe

 

[millar876]

I get about 40-42 MPG from my 2007 Vauxhall Vectra 1.8L Exclusive, and those are proper big imperial gallons not tiny small US Gallons (1 imp Gallon = 1.2 US Gallon), so thats about 48-50 miles per US Gallon, and our petrol is a higher octane, i think, Standard unleaded 95 Oct, Premium 98 Oct.

 

[Sly]

On the topic of clutches and shifting, how do you all shorten your time between 1st and 2nd when you're off the gas and shifting (where the gap in acceleration is most noticeable?)

I never realized the pause was such a big deal until yesterday I'm accelerating from a stop, and the schmuck behind me nearly plows into me before getting into the lane next to me, flipping me off, and speeding off. Or is this just a one-off scenario of a guy being a dick?

For the smoothest changes don't actually come right off the gas, just a slight lift to drop the revs down so the revs match what is required for the next gear. If going down through the box a slight blip on the throttle is needed to up the revs for perfect synchronization. Doing this will automatically speed up your gear change time as the shift will be smooth, it also reduces clutch and drive train wear and keeps your passengers happy with a more comfortable ride.

The guy was being a complete idiot as you say. Even if you were accelerating erratically, or even braking instead of accelerating, he should have left enough distance behind you to allow him to react accordingly.

 

[Love]

05 V6 Honda Accord gets about 25-27 MPG (higher than rating) in City, and gets about 32-40 on the highway.

We don't drive our Tahoe anymore because it essentially needs a constant gas tube in it.

In all actuality, about 13/14.7 ct/hw for the Tahoe.

 

[xboxer75010]

I drive a 1990 VW Fox 1.8L. I average about 28-30 and that with it having the timing way over advanced, and it having some of vacuum leaks. Car has about 265k on the clock.

 

[IJ Reilly]

I get about 40-42 MPG from my 2007 Vauxhall Vectra 1.8L Exclusive, and those are proper big imperial gallons not tiny small US Gallons (1 imp Gallon = 1.2 US Gallon), so thats about 48-50 miles per US Gallon, and our petrol is a higher octane, i think, Standard unleaded 95 Oct, Premium 98 Oct.

Actually, more like 33 MPUSG, since imperial gallons are larger. You won't find 95 or 98 octane rated gasoline in the US anywhere any longer (at least I don't think so), but the method of rating octane in the US and just about everywhere else is different. Your fuel is rated by the Research Octane Number (RON). Ours is rated as the average of RON and the Motor Octane Number (MON), which is why our numbers are lower.

 

[Lord Blackadder]

You won't find 95 or 98 octane rated gasoline in the US anywhere any longer (at least I don't think so)

Shell V-Power is rated 95 octane in NE Ohio, and I have seen some gas stations that sell "race fuel" rated at 100 octane. It might just be avgas.

 

[IJ Reilly]

Shell V-Power is rated 95 octane in NE Ohio, and I have seen some gas stations that sell "race fuel" rated at 100 octane. It might just be avgas.

Could be, but avgas is leaded, so I don't think it's legal to sell it for automotive use.

 

[Lord Blackadder]

Could be, but avgas is leaded, so I don't think it's legal to sell it for automotive use.

Really? I thought they switched to unleaded...Not sure though. I'm pretty sure avgas is legal to sell for non-road going cars (i.e. race cars).

Cars that require premium fuel cost more to fill up, so even if they get over 30mpg the extra energy and money it costs to produce 91+ octane fuel offsets the savings somewhat.

 

[yg17]

Could be, but avgas is leaded, so I don't think it's legal to sell it for automotive use.

AFAIK, the 100+ octane stuff is leaded but only for specialty use like race cars and not road cars. I know the only place around here that sells that kind of gas is the local dragstrip.

 

[Sly]

In the UK standard unleaded is 95 octane , super is 98 (BP) or 99 octane (shell).