Site News - 11/25: Special Ad Rate | 11/1: Members: Log In to See Fewer Ads!
[General | Members | C900 | 9000 | NG900 & OG93 | 93 | 95 | NG95 | 99 | Sonett | Vintage Models | Clubs | Other Cars | FAQs | Gifts | Member Photo Galleries | Member Directory | Classifieds | Manuals | *Buddy Registry | *Mileage Registry | Polls | What's New | Raffle | Photo of the Month | Sponsors]

General Bulletin Board
[Subscribe to Daily Digest]
(Search Author's Posts: e.g. Keyword:username)*Members Only

[Main General Bulletin Board | BBFAQ | Prev by Date | Next by Date | Post Followup ] Member Login / Signup - Members see fewer ads. - Latest Member Gallery Photos
Re: I know it does: but how much does weight really affect
Like This Post: - Subscribe to Daily Digest for this Bulletin Board
Posted by Ari [Email] (#2847) [Profile/Gallery] (more from Ari) on Tue, 3 Jun 2003 13:45:22 Share Post by Email
In Reply to: I know it does: but how much does weight really affect, anthony, Mon, 2 Jun 2003 20:07:41
Alert me when someone posts in this thread:
Members do not see ads below this line. - Help Keep This Site Online - Signup

Weight directly affects acceleration. It just plain takes more energy to accelerate more mass at the same rate. So to get the same performance, you're going to dip into the throttle more, using more gas.

Going up hills takes more power, and therefore uses more fuel. From a pure physics standpoint, a car on top of a hill has more potential energy than one at the bottom. To get from the bottom to the top, you need to add energy, which comes from using fuel. The potential energy is directly related to weight. Put it this way - do you work harder lifting 5 pounds or 100 pounds over your head?

OK, so you say you get that energy back going down hill. Well, not really. If you use the brakes to maintain your speed going downhill, you're throwing that energy away as heat. If you use engine braking, you're foot is off the gas either way, and again the energy ends up as heat.
So instead, don't slow down - after all, the heavier car will go faster down the hill, and you'll recover all the energy. Well, not quite. Wind resistance increases with the cube of speed, so the faster you go, the more energy you throw away in drag.

Oh yeah, the heavier car probably has wider tires, with more rolling resistance.

Of course, you're talking about SUV's so a couple of hundred pounds is a small percentage of the weight, as as Michael says aerodynamics is probably more important when you're comparing one large brick to another. On a car, it starts to add up.

But weight is important, and don't put your stock in performance figures. How were the vehicles equipped? You can easily have a couple of hundred pounds different in optional equipment. Performance figures are always suspect - from a car magazine, they only test one vehicle. Was that one representative of the breed, or a little slower or faster? Tester skill can easly add or subtract a half-second 0-60.

And last one about performance - very true for SUV's. Accelerating is easy. Stopping is what counts, especially when it comes to not hitting things. The heavier the vehicle, the harder it is to stop. You either need bigger brakes, or longer stopping distances.

There is a very good reason why Colin Chapman (Lotus) lived by his motto - "Add Lightness".



posted by 192.249....
Posts in this Thread:
Alert me when someone posts in this thread:
Members do not see ads below this line. - Help Keep This Site Online - Signup
Post a Followup

No Site Registration is Required to Post - Site Membership is optional (Member Features List), but helps to keep the site online
for all Saabers. If the site helps you, please consider helping the site by becoming a member.

Name: Member Login / Signup - Members see fewer ads. - Latest Member Gallery Photos
E-Mail: (Optional)
Re-Enter E-Mail: (Confidential & Secure - Not revealed to other users!)
Note: Please check your spam folder for BB responses.

Subject:

Posting rules are simple - No for sale/wanted ads may be posted here - use the site classifieds.
You may not cross-post your message to multiple BBs.
Not permitted: political/religious topics and being disrespectful (personal attacks, insults, etc...).
 Site Members do not see any red text, inline ad links, bottom of page anchor ads, box ads, or anti-spam check.

Message: (please no for sale/wanted classifieds - post those in the Saabnet.com Classifieds)
Links are now automatically made active, no need for any special code (or use the Option Link field below) - don't put links in () or end with a '.'
To add inline images to your post, use [img]http://www.domain.com/img.jpg[endimg] (or use the Optional Image Link field below).

Links are now automatically made active, no need for any special code (or use the Option Link field below) - don't put links in () or end with a '.'
To add inline images to your post above, use [img]http://www.domain.com/img.jpg[endimg] (or use the Optional Image Link field below).
Optional Link: (e.g. http://www.saabnet.com/)
Link Title: (Optional)
Optional Photo/Image Link: (e.g. http://www.saabnet.com/img.jpg)
Photo/Image to Upload: (Please be patient while file uploads)



StateOfNine.com
SaabClub.com
Jak Stoll Performance
M Car Covers
Ad Available

The content on this site may not be republished without permission. Copyright © 1988-2026 - The Saab Network - saabnet.com.
For usage guidelines, see the Mission & Privacy Notice.
[Contact | Site Map | Saabnet.com on Facebook | Saabnet.com on Twitter | Shop Amazon via TSN | Site Donations]

Random Saabnet.com Member Gallery Photos (Click Image)
This is a moderated bulletin board - Posting is a privilege, not a right. Unsolicited commercial postings are not allowed (no spam). Please, no For Sale or Wanted postings, SERIOUSLY. Classifieds are to be listed in The Saab Network Classifieds pages. This is a problem solving forum for over 250,000 Saab owners, so expect to see problems discussed here even though our cars are generally very reliable. This is not an anything goes type of forum. Saabnet.com has been a moderated forum since 1988. For usage guidelines, see the Saabnet.com Mission and Purpose Page. Please remember that you are not anonymous. Site Contact | Site Donations | Other Sites by SP - Poverty2Prosperity.org | Run Club Menlo Park | ScreenBot


Site Members do not see red text instructions, bottom of the page anchor ads, or box ads.
Click here to see all the Site Membership Benefits!