Gas consumption in reverse

gasoline
saab
900
fuel-economy

#1

I just read in Reader’s Digest that some can improve gas mileage by 25% by not putting their car in reverse. This seems like an exaggeration, how can putting a car in reverse be that bad… like 25% bad?



Thanks,





Damien





Source: http://www…ey-on-gas/


#2

Not using reverse saving 25% in gas?? Utter nonsense. First I’ve ever heard of it, and I’d love to see who the ‘experts’ were that came up with it.

I also question the ‘10 second’ rule for shutting off your engine when stopped. That’ll result in lots of stop/starts, lots of wear on the starter, and lots of opportunities for problems in traffic. One minute would be my interval.


#3

From the article:
Quote:
1. Go forward.

Always park so that you can pull forward rather than waste gas backing up. This can improve your mileage 25 percent (some experts say this might be an underestimate)!

Endquote

Utter nonsense. If you include the distance you back up - which new cars do, only much older cars don’t; you can tell by the speedometer, it goes negative on the cars that don’t - then there’s little to no differnce.

You’d have to to a heck of a lot of “backing up” for it to come to 25%, and then ignore all that distance in the process.

I’d agree with the minute estimate for gasoline powered engines. Totally different for diesels - it takes more fuel to start than it does to idle for 30 minutes (using older information on rigs, not todays cars, so may not be 100% accurate today).


#4

I assume they mean by putting your car in Neutral rather than Reverse (for example, backing down your drive) you will save 25% during that short trip. They don’t mean 25% in overall mileage.


#5

Years Ago I Was A RD Reader, But That Rag Is No Longer What It Once Was.

According to that article I can increase my mileage up to 19% by maintaining my car, 25% by not using reverse, up to 55% by going the speed limit and driving smoothly and 7% more for using cruise control, and up to 19% by not idling more than ten seconds.

If I do all those things (and that’s just in the first 3 numbered suggestions out of 5) . . .
I can improve my MPG by 125% !

My Bonneville will get better mileage than a little hybrid. That’s fantastic news.

Did I mention that I don’t read RD any longer ?

CSA


#6

I guess an argument can be made that if you are in reverse you are not moving towards your destination, so gas is wasted. I really thought this would be a post about how to make more gas appear in your tank.


#7

You know what happens when you “assume”…

Besides, how many households have circular drives where you can pull in, and then pull out? Sure, there are some, but the vast mojority are fairly flat, and do not have circular drives.

I’ll grant you engines can work harder in reverse, but you shouldn’t be trying to break speed limits in reverse, either.


#8

“I really thought this would be a post about how to make more gas appear in your tank.”

Oldschool, I’ll bet you just nailed the article for next month’s mag.

: - )
CSA


#9

Even if you got 10,000% WORSE gas mileage while driving in reverse then going forward…you’d still wouldn’t get a 25% increase by NOT driving in reverse. I average 35k miles a year…I’d be very very surprised if of that 35,000 miles more then 1 mile was while I was in reverse.


#10

Reader’s Digest prints a lot of fiction. This is “fairy tale” fiction.


#11

Why even drag the extra weight around if it is only going to be used so infrequently, take that baby out and probably get another 5% (and a hernia from pushing your car).


#12

Maybe a better question to ask is: “What would cause greater fuel consumption in a reverse gear?”


#13

“What would cause greater fuel consumption in a reverse gear?”

It’s a lower gear…But how many miles do you drive a year in Reverse? If more then 10 miles a year…then WHY do you drive so much in reverse?? 10 miles a year in reverse is a LOT…


#14

Years Ago I Was A RD Reader, But That Rag Is No Longer What It Once Was.

According to that article I can increase my mileage up to 19% by maintaining my car, 25% by not using reverse, up to 55% by going the speed limit and driving smoothly and 7% more for using cruise control, and up to 19% by not idling more than ten seconds.

If I do all those things (and that’s just in the first 3 numbered suggestions out of 5) . . .
I can improve my MPG by 125% ! "

Actually, what would happen, is that your tank would overflow!


#15

These ignorant stories are put out there every single day and sadly enough, countless thousands or millions of people will read it and take it as the truth. It’s just another garbage story.

Another one is the story that Motor Trend published a year or two ago, and stands firmly behind, is the one about the 2010 Mustangs going to LED taillamps and saving 10 gallons of gas a year as compared to the 2005-2009 Mustangs with incandescents. (Based on a Sylvania statement. Whether Sylvania paid MT a fee to publish this tripe I have no idea but you can safely assume Sylvania and MT will never cop to it.)

My daughter had LED taillamps installed in her '05 Mustang (for appearance purposes only) and her fuel mileage improved not one iota because of it.
That story made me wonder how many people ran out and bought LEDs lamps after reading that load of crap.
By that logic this means that fuel economy should skyrocket upwards if one confines their driving to daylight hours and never turns on any lamps at all.


#16

Maybe the author watched that movie 'Smoke Signals" with the two women who drive an old beater everywhere in reverse.


#17

This is simply TOTAL NONSENSE…The reverse gear is akin to first gear in your tranny. Mmm Maybe like 2nd gear as I have many x hit Ludicris Speed in reverse…faster that first gear would have permitted so… I DO think that OK nailed it…You are no longer travelling toward your destination so it is wasted fuel…lol.most people simply idle in reverse so it shouldnt cause a mileage issue…WHAT TOTAL BS…


#18

By that logic this means that fuel economy should skyrocket upwards if one confines their driving to daylight hours and never turns on any lamps at all.

Well, 746W=1HP, and 1 gallon of gas will produce 20HP for an hour (in a fairly efficient engine).

So, if you assume 50% alternator efficiency, every 40W you “shed” will save around 1 gallon gas per 200 hours of operation, or per 6,000 miles (mixed city/HWY use).


#19

With all due respect I don’t think calculator theory translates to a real world situation.
The only affect on fuel mileage would be any increased magnetism in the alternator due to incandescent bulb use as compared to LEDs. The difference would be so slight as to be completely or nearly non-existent.

If alternator load is the criteria for fuel mileage then why is it my cars get the same fuel mileage at night with all lighting and A/C on as it does during the day with no lighting and no A/C use?
The electrical load difference is far greater in that situation than in an incandescent/LED scenario.

My daughter is supposed to bring her car out in a week or so for some routine maintenance so I’ll have her bring her old incandescent lamps with her. I’ll check the current load on both sets and test the alternator to see if if it makes one iota of difference.
Since her car is one that is claimed to benefit from this modification it will be interesting to see if anything noticeable crops up at all.


#20

Let’s do an example and see what our mpgs in reverse must be:
Assume 100 feet/day in reverse = about 7 miles/year
Assume 12,000 miles/year total
Assume 20 mpg total

If eliminating reverse raises mpgs by 25%, then we’d get 25 mpg by doing it.
So 25 mpg in 12,000 miles = 480 gallons
And 25 mpg in 11,993 miles = 479.7 gallons + ? in 7 miles = 20 mpg in 12,000 miles = 600 gallons
So we’d have to use 600 - 479.7 = 120.3 gallons in 7 miles, or 0.06 MPG!!

That’s 17 GALLONS PER MILE!!!

I don’t thinks so, do you?