Re: Manual trans driving, saving fuel - coast or downsh - Saab General Bulletin Board - Saabnet.com
Click Banner for Details on this Saabnet.com Classified
The banner above is an advertisment - if it asks you to download software, please ignore.
Site News -
[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: Manual trans driving, saving fuel - coast or downsh
Like This Post: - Subscribe to Daily Digest for this Bulletin Board
Posted by jp (more from jp) on Wed, 15 Mar 2006 13:40:41 Share Post by Email
In Reply to: Manual trans driving, saving fuel - coast or downshift?, Caarma [Profile/Gallery] , Wed, 15 Mar 2006 13:06:19
Alert me when someone posts in this thread:
Members do not see ads below this line. - Help Keep This Site Online - Signup

On a Saab with T7 or newer, it's probably not a noticable difference. The Drive-by-wire thing saves fuel and reduces emmisions while downshifting by creating slower engine rev changes

The car doens't engine brake well because of this. Try measuring speed change over a fixed distance sometime with moderate engine braking in a newer saab. It will be very similar speed change to coasting over the same section of road.

On an older Saab, I would instictively favor coasting as the better fuel saver. The more gradual the speed drop in the lower speed range, the better, since air resistance changes are squared according of the speed.
Any kinetic energy motion also obeys the same rule.

On any car, fuel is needed to keep the engine going, sometimes not much. Ever had a 100% fuel cutout while in gear? My classic 900t used to cut out fuel when under inordinate (but intentional) boost. My XJS I used to have had a fuel cutoff inertia sensor by my left leg and I hit it once by accident when the cover was not on it. You stop pretty quick. My 900t also had the a failed alternator once and when the battery was done, it couldn't ignite the fuel, so it slowed down real quick. Fortunately, I was on a hill and could coast a mile closer to home by taking it out of gear. I didn't shut the car off instinctively, as some cars lock their steering column when shut off!

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 © 1988-2024 - 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!