Is this normal for a heavy car? - Fuelly Forums

Android Users - Coming Soon! - Migrating from aCar 4.8 to 5.0

Reply
 
Thread Tools Display Modes
 
Old 07-03-2007, 04:19 PM   #1
Senior Member
 
Join Date: Jul 2010
Posts: 278
Country: United States
Location: CT
Is this normal for a heavy car?

Righto, just something I noticed when I'm driving on nearly any road (Except perfectly flat)

Even the slightest upward grade can have a massive effect on my FE. Going 65 down the highway, I'll get anywhere from 45 to 25 mpg, depending upon the slope. (And we're not talking about massive changes. I live in Northern Indiana for pete's sake. The slopes are barely there at all...)

Is it due to the fact that I have a heavy (3500lb), but aerodynamic(.35 drag coefficient) car that my biggest effect is caused by slope? (From 55 to 65, I see maybe a 2-3 mpg loss, but on a slight uphill, I can get a 10mpg loss)

I've stripped out all loose items and have essentially an empty car.

I've got my tires at around 40 psi. Would upping them to 45(sidewall max) have much an effect? What would likely show the most dramatic effect on my FE that I could do?
__________________

Wyldesoul is offline   Reply With Quote
Old 07-03-2007, 04:28 PM   #2
Registered Member
 
GasSavers_Red's Avatar
 
Join Date: Nov 2006
Posts: 513
Country: United States
Send a message via MSN to GasSavers_Red
Turbo spooling up maybe making you run rich?
__________________

__________________
GasSavers_Red is offline   Reply With Quote
Old 07-03-2007, 05:44 PM   #3
Registered Member
 
Join Date: Mar 2007
Posts: 1,138
Country: United States
Quote:
Originally Posted by Biffmeistro View Post
Is it due to the fact that I have a heavy (3500lb), but aerodynamic(.35 drag coefficient) car that my biggest effect is caused by slope?
Ya, this makes sense to me. But the turbo seems like a possible culprit as well....
__________________
Bill in Houston is offline   Reply With Quote
Old 07-03-2007, 06:29 PM   #4
Senior Member
 
Join Date: Jul 2010
Posts: 278
Country: United States
Location: CT
Nah, turbo doesn't spool. My vaccuum level goes more towards 0, but only on a very steep hill do I see boost.
Wyldesoul is offline   Reply With Quote
Old 07-03-2007, 06:48 PM   #5
Senior Member
 
Join Date: Jul 2010
Posts: 278
Country: United States
Location: CT
Ah yes, and I shall clear up a little what I meant.

I don't cruise at 45mpg, I cruise at around 35. Just with the cruise control on, slight slopes will make it drop down to 25 (going up) and jump to 45(Going down)

Sometimes it can be as much as drop to 20, raise to 50 (And that's not counting when I put it in neutral and coast. Then it jumps to 100+mpg)
Wyldesoul is offline   Reply With Quote
Old 07-03-2007, 07:55 PM   #6
Registered Member
 
basjoos's Avatar
 
Join Date: Mar 2006
Posts: 392
Country: United States
The slope effect also hits lighter cars. Slope has a much bigger effect than speed on my civic. I have to either let my speed drop or accept a drop in mileage on a slope. If I am getting 90mpg at 65mph on the flat, the mileage can easily drop to 40 to 50mpg on a slight upslope and rise to 140 to 160mpg on a slight downslope.
__________________
]
aerocivic.com
basjoos is offline   Reply With Quote
Old 07-03-2007, 08:04 PM   #7
Registered Member
 
VetteOwner's Avatar
 
Join Date: Mar 2007
Posts: 1,546
Country: United States
what car is it?
VetteOwner is offline   Reply With Quote
Old 07-03-2007, 08:25 PM   #8
Senior Member
 
Join Date: Jul 2010
Posts: 278
Country: United States
Location: CT
My T-bird. 87 turbocoupe.
Wyldesoul is offline   Reply With Quote
Old 07-03-2007, 09:33 PM   #9
Registered Member
 
VetteOwner's Avatar
 
Join Date: Mar 2007
Posts: 1,546
Country: United States
ahh the ol thunder chicken!
VetteOwner is offline   Reply With Quote
Old 07-04-2007, 11:16 AM   #10
ELF
Registered Member
 
ELF's Avatar
 
Join Date: Jan 2007
Posts: 245
Country: United States
Biffmeistro, I have the same problem as you, On my sable. Fill your front tires up a little more psi, Possibly consider a air dam or belly pan to improve areo.
This is how I can tell if my gas is good or bad, the amount the mpg drops on slight uphills, Good gas I can keep it up around 28-30 uphill, when I get some bad tanks of gas my mpg drops way down to 22-24 on the same hill. I think due to excessive moisture in the ethanol.
Try to speed up slightly before the hill and try to lighten up on the throttle while climbing the hill even if you drop some speed, try to recoup the speed when going down hill.
__________________

__________________
ELF is offline   Reply With Quote
Reply

Thread Tools
Display Modes

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Trackbacks are Off
Pingbacks are Off
Refbacks are Off


Similar Threads
Thread Thread Starter Forum Replies Last Post
Fuelly badge not updating for about 2 - 3 weeks Need Fuelly Web Support and Community News 18 07-01-2012 03:01 PM
Fuelly Android App - eehokie Fuelly Web Support and Community News 2 07-14-2010 09:59 PM
VW Jetta fast riser coolbreeze General Fuel Topics 5 07-22-2009 12:25 AM
DIY: Wire Tuck!!! SVOboy Experiments, Modifications and DIY 11 09-21-2006 05:17 AM
Condensator orevgym General Fuel Topics 0 07-23-2006 11:25 AM

Powered by vBadvanced CMPS v3.2.3


All times are GMT -8. The time now is 09:31 PM.


Powered by vBulletin® Version 3.8.8 Beta 1
Copyright ©2000 - 2017, vBulletin Solutions, Inc.