Notices
C5 General General C5 Corvette and C5 Z06 Discussion not covered in Tech

MODS that increase MPG??

Thread Tools
 
Search this Thread
 
Old Aug 13, 2010 | 06:05 PM
  #1  
mel3535's Avatar
mel3535
Thread Starter
Burning Brakes
15 Year Member
Conversation Starter
All Eyes On Me
 
Joined: Feb 2010
Posts: 1,037
Likes: 0
From: Alameda CA
Default MODS that increase MPG??

Are there any mods that help with your MPG, just curious because my 04 coupe,a4, barely gets me 20mpg and that's with lot of freeway driving,.I have asked this question quite a few times on the forum since i bought my car about 7 months back but there seems to be nothing wrong with my 04 a4 with now almost 20k miles. Nothing has gone wrong with the car, the car is bone stock beside k&N filter and drivers perfectly fine.

Does everyone get this kind of gas mileage or am i the only one,on a full tank i usually get around 250 miles before low fuel comes up in DIC, is this normal?

20mpg is not bad at all and i did not buy a vette for good gas mileage but I hear people on here getting 30mpg and wonder why i do not.

So any mods that can help me improve mpg? and is my mpg normal or what?
Reply
Old Aug 13, 2010 | 06:09 PM
  #2  
0331MARINE's Avatar
0331MARINE
Safety Car
Supporting Member
10 Year Member
 
Joined: Oct 2007
Posts: 3,903
Likes: 1
From: You know your drunk when you swerve to miss the tree then you realize its your air freshener! Covington Ga
Default

Something isnt right. My car is over 420rwhp with a big cam and my avg is over 20mpg. Might want to start checking some things. Plugs, wires, air filter, fuel filter and so on....
Reply
Old Aug 13, 2010 | 06:12 PM
  #3  
mel3535's Avatar
mel3535
Thread Starter
Burning Brakes
15 Year Member
Conversation Starter
All Eyes On Me
 
Joined: Feb 2010
Posts: 1,037
Likes: 0
From: Alameda CA
Default

Originally Posted by 0331MARINE
Something isnt right. My car is over 420rwhp with a big cam and my avg is over 20mpg. Might want to start checking some things.
i think you were the first to comment on my thread like 5 months back, and i did have it checked by two mechanics, nothing is wrong with the car, well over 4k miles since i bought it and is now almost at 20k, the car runs fine and is stock, i have done oil change and just basic maintenance and still the mpg is the same.
Reply
Old Aug 13, 2010 | 06:14 PM
  #4  
0331MARINE's Avatar
0331MARINE
Safety Car
Supporting Member
10 Year Member
 
Joined: Oct 2007
Posts: 3,903
Likes: 1
From: You know your drunk when you swerve to miss the tree then you realize its your air freshener! Covington Ga
Default

Do you drive the crap out of it? I drive pretty hard and still get pretty good MPG for the power I have.
Reply
Old Aug 13, 2010 | 06:16 PM
  #5  
mel3535's Avatar
mel3535
Thread Starter
Burning Brakes
15 Year Member
Conversation Starter
All Eyes On Me
 
Joined: Feb 2010
Posts: 1,037
Likes: 0
From: Alameda CA
Default

Originally Posted by 0331MARINE
Do you drive the crap out of it?
i was for a while and its was mostly city driving, then it was around 15mpg i would fill the tank and in about 180 miles i would have low fuel sign on the DIC , now its like 70% on the freeway and i get about 20mpg
Reply
Old Aug 13, 2010 | 06:18 PM
  #6  
mel3535's Avatar
mel3535
Thread Starter
Burning Brakes
15 Year Member
Conversation Starter
All Eyes On Me
 
Joined: Feb 2010
Posts: 1,037
Likes: 0
From: Alameda CA
Default

Originally Posted by mel3535
i was for a while and its was mostly city driving, then it was around 15mpg i would fill the tank and in about 180 miles i would have low fuel sign on the DIC , now its like 70% on the freeway and i get about 20mpg
not even 15mpg, its was 13.5

this was my thread a few months back

http://forums.corvetteforum.com/c5-g...prove-mpg.html
Reply
Old Aug 13, 2010 | 06:18 PM
  #7  
BigTattooMan's Avatar
BigTattooMan
Melting Slicks
 
Joined: Apr 2009
Posts: 2,772
Likes: 3
From: Gastonia NC
St. Jude Donor '10
Default

Just for kicks get on the freeway, set the cruise and set the DIC to instant MPG. I know it's super accurate but I'm curious how much influence your right foot is playing into this
Reply
Old Aug 13, 2010 | 06:21 PM
  #8  
mel3535's Avatar
mel3535
Thread Starter
Burning Brakes
15 Year Member
Conversation Starter
All Eyes On Me
 
Joined: Feb 2010
Posts: 1,037
Likes: 0
From: Alameda CA
Default

Originally Posted by BigTattooMan
Just for kicks get on the freeway, set the cruise and set the DIC to instant MPG. I know it's super accurate but I'm curious how much influence your right foot is playing into this
at 70 miles the dic says 26mpg.Believe me i drive this car like its a prius or something, i never get on it any more when i was i was geting 13.5 mpg

and beside i always use cruise control which is set at 70 most of the time
Reply
Corvette Stories

The Best of Corvette for Corvette Enthusiasts

story-0

150 hp to 1,250 hp: Every Corvette Generation Compared by the Specs That Matter

 Joe Kucinski
story-1

8 Coolest Corvette Pace Cars (and Replicas) of All Time

 Verdad Gallardo
story-2

Top 10 Corvette Engines RANKED by Peak Torque (70+ Years of Muscle!)

 Joe Kucinski
story-3

Corvette ZR1X Will Be Pacing the Indy 500, And Could Probably Race, Too!

 Verdad Gallardo
story-4

Top 10 Corvettes Coming to Mecum Indy 2026!

 Brett Foote
story-5

Top 10 C9 Corvette MUST-HAVES to Fix These C8 Generation Flaws!

 Michael S. Palmer
story-6

10 Revolutionary 'Corvette Firsts' Most People Don't Know

 Joe Kucinski
story-7

5 Reasons to Upgrade to an LS6-Powered Corvette; 5 Reasons to Stay LT2

 Michael S. Palmer
story-8

2027 Corvette vs The World: Every C8 vs Its Closest Competitor

 Joe Kucinski
story-9

10 Most Common Corvette Problems of the Last 20 Years!

 Joe Kucinski
Old Aug 13, 2010 | 06:22 PM
  #9  
REDEVIL's Avatar
REDEVIL
Burning Brakes
20 Year Member
Liked
Loved
Community Favorite
 
Joined: Nov 2002
Posts: 1,178
Likes: 240
From: Huntington Beach CA
Default

Originally Posted by mel3535
i was for a while and its was mostly city driving, then it was around 15mpg i would fill the tank and in about 180 miles i would have low fuel sign on the DIC , now its like 70% on the freeway and i get about 20mpg
I'm right there with you. Lately I've been driving 60-70% freeway in Southern California and I get about 18-20 mpg. I have Long Tube headers, cat back, vararam and dyno tune. Even on my trip to Vegas last month I only got 25 mpg. I don't see how people are always posting that they get 30+ mpg. Could it be the gas is different out here? When I lived in KS I would always put in 93 octane, but only 91 is available in Southern California.
Reply
Old Aug 13, 2010 | 06:26 PM
  #10  
0331MARINE's Avatar
0331MARINE
Safety Car
Supporting Member
10 Year Member
 
Joined: Oct 2007
Posts: 3,903
Likes: 1
From: You know your drunk when you swerve to miss the tree then you realize its your air freshener! Covington Ga
Default

I'm only about an hour or so south of you..
Reply
Old Aug 13, 2010 | 06:38 PM
  #11  
Jet-Jock's Avatar
Jet-Jock
Race Director
Supporting Lifetime
10 Year Member
 
Joined: Aug 2003
Posts: 13,421
Likes: 8
From: Lake Mary Florida
Default

26 at highway speeds is close, the window sticker says 19/28.

Have you reset the Average while on the highway and drive for a bit to let it re-establish average?

What type and size of tires (if different from stock)?

What type/octane fuel?

What mileage?

When was the last plug/wire replacement (mileage) if it has been done and if so what wires and plugs were installed?

When was the last time the air filter and PCV was changed?
Reply
Old Aug 13, 2010 | 06:40 PM
  #12  
mel3535's Avatar
mel3535
Thread Starter
Burning Brakes
15 Year Member
Conversation Starter
All Eyes On Me
 
Joined: Feb 2010
Posts: 1,037
Likes: 0
From: Alameda CA
Default

Originally Posted by REDEVIL
I'm right there with you. Lately I've been driving 60-70% freeway in Southern California and I get about 18-20 mpg. I have Long Tube headers, cat back, vararam and dyno tune. Even on my trip to Vegas last month I only got 25 mpg. I don't see how people are always posting that they get 30+ mpg. Could it be the gas is different out here? When I lived in KS I would always put in 93 octane, but only 91 is available in Southern California.
did the mpg change after the mods? i would think that with CAI and a tune you might be geting higher MPG
Reply
Old Aug 13, 2010 | 06:44 PM
  #13  
mel3535's Avatar
mel3535
Thread Starter
Burning Brakes
15 Year Member
Conversation Starter
All Eyes On Me
 
Joined: Feb 2010
Posts: 1,037
Likes: 0
From: Alameda CA
Default

Originally Posted by Jet-Jock
26 at highway speeds is close, the window sticker says 19/28.

Have you reset the Average while on the highway and drive for a bit to let it re-establish average?

What type and size of tires (if different from stock)?

What type/octane fuel?

What mileage?

When was the last plug/wire replacement (mileage) if it has been done and if so what wires and plugs were installed?

When was the last time the air filter and PCV was changed?
i reset my avg in the DIC everytime i fuel up and reset my trip A so i know how many miles i get on a full tank,

tires are stock good year f1

fuel is 91

about to hit 20k miles and the car was 15854 when i got t

oil and filter along with air filter changed in the last 2k

if i start the car and look where the needle is on the gas gauge then turn it off and start again most of the time the needle goes donw a little or will if i do that 2 or 3 times, does that have something to do with spark plugs or anything like that, it seems to me that i burn a lot of fuel every time i start the car
Reply
Old Aug 13, 2010 | 06:55 PM
  #14  
REDEVIL's Avatar
REDEVIL
Burning Brakes
20 Year Member
Liked
Loved
Community Favorite
 
Joined: Nov 2002
Posts: 1,178
Likes: 240
From: Huntington Beach CA
Default

Originally Posted by mel3535
did the mpg change after the mods? i would think that with CAI and a tune you might be geting higher MPG
It's hard to say because when I got the headers and tune, I swapped the automatic for an M6, so I wouldn't be comparing apples to apples. I think my car gets OK mileage, but not the 30+ that some people claim here. I'm not too worried about it, but it makes me feel better when others are closer to the manufacturers claim of 28 mpg highway.
Reply
Old Aug 13, 2010 | 07:10 PM
  #15  
renegad44's Avatar
renegad44
Safety Car
 
Joined: Aug 2007
Posts: 4,506
Likes: 0
From: This is not a Song, It's an Outburst: Or, The Establishment Blues; Sixto Diaz Rodriguez
Default

I don't have many mods, except the few in my signature, and I have only managed, I recall 25.3MPG on a road trip, a/c on, to my daughter in Frisco Texas. Usually on those road trips, I don't play with it (WOT) because of the amount of added weight of a little luggage, and stuff I bring to my daughter, in other words, to me, too much weight to worry about WOT, and that's the best I do on open highways. No complaints though, I'm satisfied.
Reply
Old Aug 13, 2010 | 07:15 PM
  #16  
Jet-Jock's Avatar
Jet-Jock
Race Director
Supporting Lifetime
10 Year Member
 
Joined: Aug 2003
Posts: 13,421
Likes: 8
From: Lake Mary Florida
Default

On the reset at fill the area I'm trying to avoid is any interim city driving being calculated. If you're seeing 26's on instant, I'd like to see it reset then, continue driving and see what the average is when you exit the interstate (highway).

This vehicle is still a baby practically.

Sounds like you have corrosion building up on the fuel sender contacts, typical problem as a result of the design. This is why you hear folks talk about adding Techron or using gas with Techron because it cleans the contacts and fixes the irregular fuel level readings. You can use exclusively Chevron or Texaco Supreme or buy a bottle of Techron at the parts store and add it according to the label instructions.

20K on maximum performance tires is about right, so not seeing the tread remaining you probably are getting close to new tires soon. Those OEM EMTs have a 300 wear rating. So you've gone through a good portion of the soft rubber, they are probably getting a little noisy now and perhaps a little more bump steer effect. A new tire especially some of the newer generation tires will give you a little improvement in that MPG say 1-2. But as that tire wears you'll be back to the 26 area. Depending on your type of driving and if you want to remain with run flats, Michelin Pilot Sport A/S ZPs or the Pilot Sport PS2 ZP will suit the vehicle. Going to a non run flat will further increase your gas mileage.
Reply
Old Aug 13, 2010 | 07:20 PM
  #17  
Jet-Jock's Avatar
Jet-Jock
Race Director
Supporting Lifetime
10 Year Member
 
Joined: Aug 2003
Posts: 13,421
Likes: 8
From: Lake Mary Florida
Default

Originally Posted by REDEVIL
It's hard to say because when I got the headers and tune, I swapped the automatic for an M6, so I wouldn't be comparing apples to apples. I think my car gets OK mileage, but not the 30+ that some people claim here. I'm not too worried about it, but it makes me feel better when others are closer to the manufacturers claim of 28 mpg highway.
Different back pressure values will affect gas mileage but you also have a tune, that can be adjusted some. What tires are you running. MN6 will get better gas mileage then the A4s.

You really have to work at hitting those high numbers, finding the sweet spot at cruise over a period of time to get the highest value. But you should be in the range of the 26-28 range in normal type highway driving.
Reply

Get notified of new replies

To MODS that increase MPG??

Old Aug 14, 2010 | 10:19 AM
  #18  
burbleflyer's Avatar
burbleflyer
Drifting
20 Year Member
Conversation Starter
All Eyes On Me
 
Joined: Mar 2006
Posts: 1,340
Likes: 2
From: ZHills Florida
St. Jude Donor '08
Default

The only way you'll really find out what, if anything is going on, is to find someone with a wideband sniffer and get a street tune.
Reply
Old Aug 14, 2010 | 10:51 AM
  #19  
Kale's Avatar
Kale
Team Owner
25 Year Member
Conversation Starter
All Eyes On Me
Photogenic
 
Joined: Feb 2000
Posts: 51,504
Likes: 6
From: Sacramento CA
Default

I haven't found the DIC to be really accurate. You may just need to do the math.

Mine is usually 1-1.5 mpg off.

My wife's toyota, however, is always spot on. It's strange.
Reply
Old Aug 14, 2010 | 11:39 AM
  #20  
Vetteman Jack's Avatar
Vetteman Jack
Administrator
Supporting Lifetime
Veteran: Navy
St. Jude 20 Year Donor
25 Year Member
Veteran: Reserves
 
Joined: Mar 2001
Posts: 367,741
Likes: 24,678
From: In a parallel universe. Currently own 2014 Stingray Coupe.
C7 of the Year - Modified Finalist 2021
MO Events Coordinator
St. Jude Co-Organizer
St. Jude Donor '03 thru '25
NCM Sinkhole Donor
CI 5, 8 & 11 Veteran
Default

Well, chances are you won't see 30 mpg out of an A4 - the six speed cars can get that due to the two overdrives in the tranny.

I usually get around 27 mpg from my A4 out on the highway, but when doing combined city/highway driving, it drops to 23-25 mpg.
Reply



All times are GMT -4. The time now is 12:20 PM.

story-0
150 hp to 1,250 hp: Every Corvette Generation Compared by the Specs That Matter

Slideshow: From C1 to C8 we compare every Corvette generation by the numbers.

By Joe Kucinski | 2026-05-12 16:54:12


VIEW MORE
story-1
8 Coolest Corvette Pace Cars (and Replicas) of All Time

Slideshow: Some Corvette pace cars became collectible legends, while others perfectly captured the look and attitude of their era.

By Verdad Gallardo | 2026-05-11 09:50:51


VIEW MORE
story-2
Top 10 Corvette Engines RANKED by Peak Torque (70+ Years of Muscle!)

Slideshow: Ranking the top 10 Corvette engines by torque output.

By Joe Kucinski | 2026-05-05 11:58:09


VIEW MORE
story-3
Corvette ZR1X Will Be Pacing the Indy 500, And Could Probably Race, Too!

Slideshow: A Corvette pace car nearly matching IndyCar speeds sounds exaggerated, until you look at the numbers.

By Verdad Gallardo | 2026-05-04 20:03:36


VIEW MORE
story-4
Top 10 Corvettes Coming to Mecum Indy 2026!

Among a rather large group of them.

By Brett Foote | 2026-05-04 13:56:44


VIEW MORE
story-5
Top 10 C9 Corvette MUST-HAVES to Fix These C8 Generation Flaws!

Slideshow: the top 10 things Corvette owners want in the C9 Corvette

By Michael S. Palmer | 2026-04-30 12:41:15


VIEW MORE
story-6
10 Revolutionary 'Corvette Firsts' Most People Don't Know

Slideshow: 10 Important Corvette 'firsts' that every fan should know.

By Joe Kucinski | 2026-04-29 17:02:16


VIEW MORE
story-7
5 Reasons to Upgrade to an LS6-Powered Corvette; 5 Reasons to Stay LT2

Slideshow: Should you buy a 2020-2026 Corvette or wait for 2027?

By Michael S. Palmer | 2026-04-22 10:08:58


VIEW MORE
story-8
2027 Corvette vs The World: Every C8 vs Its Closest Competitor

Slideshow: 2027 Corvette lineup vs the world.

By Joe Kucinski | 2026-04-24 16:12:42


VIEW MORE
story-9
10 Most Common Corvette Problems of the Last 20 Years!

Slideshow: 10 major Corvette problems from the last 20 years.

By Joe Kucinski | 2026-04-14 16:37:05


VIEW MORE