Recent Topics
1991 Clean Acura NSX with some mods for $45k
by HTSS_TR
06/27/16 03:16 PM
Tiny metal particles suspended in oil?
by rustypigeon
06/27/16 02:35 PM
M1 0w20, 10,093 miles, 2006 Civic
by Patman
06/27/16 02:13 PM
5w-40 synthetic vs 15w-40 synthetic
by mbacfp
06/27/16 01:27 PM
SCAM!Anyone renting their water heater tank?
by KrisZ
06/27/16 01:16 PM
Donaldson PowerCore as HEPA filter?
by PeterPolyol
06/27/16 01:13 PM
Clearance oversized filters for M20x1.5 w/bypass
by PeterPolyol
06/27/16 01:05 PM
Prestone vs. DEX-COOL Concentrate
by Ramblejam
06/27/16 12:54 PM
Severe service and OEM oil Filters
by Tech819
06/27/16 12:46 PM
ContiTech Pro Series timing belt kit 2009 Galant
by Ruturaj
06/27/16 12:25 PM
Bogus Coolant Test! - did Pat Goss make a mistake?
by i_hate_autofraud
06/27/16 11:57 AM
The "zero posters"
by OVERKILL
06/27/16 11:57 AM
Newest Members
scuff, Tuar, ATFD48, Enumeratum, poc
58290 Registered Users
Who's Online
91 registered (69GTX, 901Memphis, 3for3, 01rangerxl, 1JZ_E46, 97f150, 11 invisible), 2100 Guests and 10 Spiders online.
Key: Admin, Global Mod, Mod
Forum Stats
58290 Members
66 Forums
250886 Topics
4112150 Posts

Max Online: 2862 @ 07/07/14 03:10 PM
Donate to BITOG
Page 1 of 2 1 2 >
Topic Options
#3319259 - 03/21/14 06:35 PM Better gas mileage with stiffer suspension.
Nayov Offline


Registered: 08/01/09
Posts: 815
Loc: ME
Well, why not? Shock absorbers (struts) soak up energy and turn it into heat which is wasted energy. When a car bobs up and down while going down the road, it cost energy to lift the car. Anyone who's ridden a dual suspension bicycle knows that it saps energy from the rider.

So taking this to the absurd level, would a car with no suspension render better fuel mileage? I know it would be undriveable, so it's for illustrative purposes only.

I got to thinking about this after I replaced all 4 struts on my car. It now rides dramatically harder and I'm wondering if I will see better fuel mileage.

Top
#3319262 - 03/21/14 06:40 PM Re: Better gas mileage with stiffer suspension. [Re: Nayov]
zzyzzx Offline


Registered: 05/18/12
Posts: 3261
Loc: Baltimore, Maryland, USA
This seems unlikely to me.

Top
#3319263 - 03/21/14 06:43 PM Re: Better gas mileage with stiffer suspension. [Re: Nayov]
yonyon Offline


Registered: 03/06/12
Posts: 3492
Loc: NJ, USA
It seems to me that a softer suspension would be the way to go (less energy lost compressing the suspension) for fuel economy over bumps but realistically it isn't going to add up to much. It really isn't all that much energy wasted.

For the suspension to provide a real-world benefit to fuel economy you want a setup that reduces or eliminates the need to brake before cornering. That will save you a lot more wasted energy than gliding over bumps.

Top
#3319266 - 03/21/14 06:47 PM Re: Better gas mileage with stiffer suspension. [Re: Nayov]
PandaBear Offline


Registered: 08/05/02
Posts: 13278
Loc: Silicon Valley
Compare to aerodynamics and rolling resistance, suspension loss is nothing.

A stiffer suspension means your car will bump higher and then bonce a bit stiffer than softer suspension, just how long will those "bonce around" turns into heat, but they all turns into heat eventually.

The only way I see it is a harder suspension reduce comfort, and force the driver to slow down to be more comfortable. It is like saying speed bump reduce speed and make your drive more fuel efficient.
_________________________
"You keep asking questions PandaBear and you'll end up a vegetarian like my wife" - Camu Mahubah

Top
#3319273 - 03/21/14 06:57 PM Re: Better gas mileage with stiffer suspension. [Re: Nayov]
yonyon Offline


Registered: 03/06/12
Posts: 3492
Loc: NJ, USA
This discussion has me wondering if those BMW control arm bushings that always break might be designed to do that. The front wheels, when hitting a bump while the bushings are broken, get shoved rearward and accelerate upwards more slowly so as to change less forward motion to upwards motion, then they snap up over the ridge of the bump. UFO

Top
#3319278 - 03/21/14 07:05 PM Re: Better gas mileage with stiffer suspension. [Re: Nayov]
Trajan Offline


Registered: 07/16/05
Posts: 3730
Loc: SE PA
Originally Posted By: Nayov
Well, why not? Shock absorbers (struts) soak up energy and turn it into heat which is wasted energy. When a car bobs up and down while going down the road, it cost energy to lift the car. Anyone who's ridden a dual suspension bicycle knows that it saps energy from the rider.

So taking this to the absurd level, would a car with no suspension render better fuel mileage? I know it would be undriveable, so it's for illustrative purposes only.

I got to thinking about this after I replaced all 4 struts on my car. It now rides dramatically harder and I'm wondering if I will see better fuel mileage.


A shock absorber is a mechanical device designed to smooth out or damp shock impulse, and dissipate kinetic energy.

Nothing more. Nothing less.
_________________________

Lack of harm is not proof of benefit.

There are in fact two things, science and opinion; the former begets knowledge, the later ignorance. Hippocrates





Top
#3319286 - 03/21/14 07:14 PM Re: Better gas mileage with stiffer suspension. [Re: Trajan]
Nayov Offline


Registered: 08/01/09
Posts: 815
Loc: ME
Originally Posted By: Trajan

A shock absorber is a mechanical device designed to smooth out or damp shock impulse, and dissipate kinetic energy.

Nothing more. Nothing less.


Yes, but I would add that dissipated energy (heat) is wasted and it costs fuel, but I do concede that the amount is in all probability immeasurable.

Top
#3319289 - 03/21/14 07:16 PM Re: Better gas mileage with stiffer suspension. [Re: Nayov]
Burt Offline


Registered: 01/08/09
Posts: 1238
Loc: texas
I have a hard time seeing how vertical motion/energy is converted into horizontal motion/energy by a stiffer suspension.

Kind of like hitting a hammer up or down on your car and expecting it to move forward.
_________________________
2011 RX350 38k miles
2015 Fiesta SFE eco-boost 7k miles

Top
#3319299 - 03/21/14 07:28 PM Re: Better gas mileage with stiffer suspension. [Re: Nayov]
Trav Offline


Registered: 11/20/06
Posts: 13980
Loc: MA, Mittelfranken.de
Originally Posted By: Nayov
I got to thinking about this after I replaced all 4 struts on my car. It now rides dramatically harder and I'm wondering if I will see better fuel mileage.

Go a step further and remove the shocks totally. Use the bouncing motion of the springs to run a generator to charge the batteries in a hybrid system. LOL

No. Stiffer struts wont improve fuel economy unless its a Nissan Maxima then it might get 20% more.
_________________________
ASE L1, Master. Deutsch Meisterbrief.

Top
#3319314 - 03/21/14 07:42 PM Re: Better gas mileage with stiffer suspension. [Re: Nayov]
spasm3 Offline


Registered: 05/30/10
Posts: 6293
Loc: out there
If you have to slow down more to corner and turn due to the body roll with no or really soft shocks, you will consume more energy getting back up to speed. Verses coasting at a faster rate around corners/s turns and using less fuel to accelerate from a higher exit speed due to better suspension.
_________________________
13 elantra 46k 5w30 ultra
03 chevy avalanche67k pyb
02 saturnsc1 66k 0w40 castrol
01 saturnsc1 185k being rebuilt
93 ciera 79k 5w30 havo

Top
#3319345 - 03/21/14 08:07 PM Re: Better gas mileage with stiffer suspension. [Re: Trav]
Nayov Offline


Registered: 08/01/09
Posts: 815
Loc: ME
Originally Posted By: Trav
Originally Posted By: Nayov
I got to thinking about this after I replaced all 4 struts on my car. It now rides dramatically harder and I'm wondering if I will see better fuel mileage.

Go a step further and remove the shocks totally. Use the bouncing motion of the springs to run a generator to charge the batteries in a hybrid system. LOL



It's been done! Well, a car powered road generator.

"The Road Surface Generator device is a revolutionary new device that incorporates current technology by utilizing the motion and weight of vehicles to produce clean, economical and ecologically sound electrical current. The Road Surface generator relies on kinetic energy produced by moving vehicles then transferred via a simple device located on surfaces that connect to a turbine generator to produce energy."

http://www.google.com/patents/US20080106103

Top
#3319353 - 03/21/14 08:20 PM Re: Better gas mileage with stiffer suspension. [Re: Nayov]
JHZR2 Offline



Registered: 12/14/02
Posts: 38103
Loc: New Jersey
You're assuming that you're converting potential energy of fuel to potential energy of ride height.

Perhaps a bouncy car has a worse aerodynamic profile, but I doubt it is much.

I can see savings from taking curves faster, as forward momentum can be wasted and is valuable.

Top
#3319369 - 03/21/14 08:38 PM Re: Better gas mileage with stiffer suspension. [Re: Nayov]
Trajan Offline


Registered: 07/16/05
Posts: 3730
Loc: SE PA
Originally Posted By: Nayov
Originally Posted By: Trajan

A shock absorber is a mechanical device designed to smooth out or damp shock impulse, and dissipate kinetic energy.

Nothing more. Nothing less.


Yes, but I would add that dissipated energy (heat) is wasted and it costs fuel, but I do concede that the amount is in all probability immeasurable.


How is it wasted? Shock absorbers do not power or draw power from the engine.
_________________________

Lack of harm is not proof of benefit.

There are in fact two things, science and opinion; the former begets knowledge, the later ignorance. Hippocrates





Top
#3319382 - 03/21/14 09:01 PM Re: Better gas mileage with stiffer suspension. [Re: Nayov]
Merkava_4 Offline


Registered: 01/30/07
Posts: 14319
Loc: Clovis, CA
The more you keep the car in a straight line, the better the fuel mileage will be.

A car getting tossed around from stiff suspension is going to affect its straight line.

Top
#3319401 - 03/21/14 09:28 PM Re: Better gas mileage with stiffer suspension. [Re: Nayov]
Donald Offline


Registered: 03/21/04
Posts: 16940
Loc: Upstate NY
It the suspension makes a difference at all, the wind and how much coffee the driver has had probably make double the difference as suspension.

Its pretty hard to accurately measure MPG unless you use a flow meter like Consumer Reports does.
_________________________
2015 Subaru Forester 2.5 engine/CVT
2015 Ford F250 w/Powerstroke
2001 Jeep Grand Cherokee Laredo 4.0- sold
1999 Dodge Ram 2500 w/Cummins- 4-sale


Top
Page 1 of 2 1 2 >