Home page
SPONSOR AD

Support our Vendors!  |  Advertise Here

Topic: Average MPG in rural America?

in Forum: C4 General Discussion


Already a Member?
Login
Not yet a Member?
Register for Free!

Average MPG in rural America? (1/18)
 5/15/14 10:16am
Mountaineer
Standard Member
Send Private Message

Gay, WV - USA

Vette(s):
!989 Medium blue convertible


Joined: 4/14/2013
Posts: 11

I have had my 1989 convertible for well over a year,and it's been trouble free,In fact I drive it so much that I had to upgrade to the freedom option on my collector car insurance because I put a lot of miles on it.
I see post where people state average MPG as 25-27 miles per gallon,but I get 19 average off interstate,and 21-23 on interstate 77.
The car seems to run perfect,and if I look at instant fuel rate on flat straight ground it does read 27-28 ,but on steep hills it reads 11-12 .Like I say the car runs great,and it takes very little throttle to maintain a steady speed.
I live in somewhat hilly terrain and was wondering what kind of mileage others are getting in such conditions.My car is a l98 auto 2.59 that is practically stock .Thanks


______________
Our Sponsors help support C4VR
Re: Average MPG in rural America? (2/18)
 5/15/14 12:29pm
cco
Former Member

Send Private Message

Joined: 8/16/2013
Posts: 191

Mine is about 25mpg's on the hwy and about 20 in town. I'm happy with that and she runs like a top.

C.

Re: Average MPG in rural America? (3/18)
 5/15/14 7:02pm
hcbph
Standard Member
Send Private Message

Minneapolis, MN - USA

Vette(s):
Purchased a 1986 Convert August 2013, Bright Red color with a black top, it'd already received a Tremec 5 speed upgrade along with a disc upgrade prior to purchase.


Joined: 8/16/2013
Posts: 53

The only real distance driving I've done so far is when I bought it (1300 miles).

I got best of 32 mpg out of it on the highway at 75 driving from N.M. to Mn.

Re: Average MPG in rural America? (4/18)
 5/16/14 8:12pm
Mountaineer
Standard Member
Send Private Message

Gay, WV - USA

Vette(s):
!989 Medium blue convertible


Joined: 4/14/2013
Posts: 11

It may be due to the fact that it's an automatic,but It doesn't get such poor mileage that it prevents me from driving it ,but it would be nice if it got what everyone else seems to get.Premium is nearly $4.oo per gallon here,and it seem that ALL gas around here has that ethanol in it.


______________
Re: Average MPG in rural America? (5/18)
 5/17/14 7:24am
hcbph
Standard Member
Send Private Message

Minneapolis, MN - USA

Vette(s):
Purchased a 1986 Convert August 2013, Bright Red color with a black top, it'd already received a Tremec 5 speed upgrade along with a disc upgrade prior to purchase.


Joined: 8/16/2013
Posts: 53

Question - why are you putting premium in your Vette?  If you have the L98 as you said, it's unmodified then it should have 9.5-1 compression ratio.  That should run on 87 octane regular just fine.  You're not getting any benefit by running premium and actually may be hurting things because you want higher compression or something like a blower to take advantages of the characteristics of premium.

I admit that gasohol is hard on rubber parts but even if you have to fuel with non-alcohol gas for collector cars and small engines, it's still cheaper here than paying for premium. Having said all that, with a 2.59 gear ratio, I would expect yours to do very well on the highway using cruise.  Now all this depends also on driving style, if you're a stoplight racer it will kill gas mileage every time.

Mine has the same compression ratio and I've been burning 87 octane in it since I bought it last year except when I put it into winter storage last fall.  Then I used non-alcohol gas.  It drives just fine on 10-15% gasohol.

Just my 2 cents.



|UPDATED|5/17/2014 4:24:03 AM (AZT)|/UPDATED|
Re: Average MPG in rural America? (6/18)
 6/14/14 8:57am
We Gone
Standard Member
Send Private Message


Vette(s):
1991 ZR-1, 1993 ZR-1, 1995 LT1, 1982 CE,


Joined: 10/31/2013
Posts: 26

Both my 91 & 93 ZR-1s get about 17-19 around town and 24-26 on the interstate.

|UPDATED|6/14/2014 5:57:46 AM (AZT)|/UPDATED|


______________

1991 ZR-1 # 118 SW Headers/Corsa-3:73 gears-Haibeck-510HP/350 1993 ZR-1 # 179 Yellow/ White- Haibeck tune, Flowmasters

Re: Average MPG in rural America? (7/18)
 6/15/14 12:20pm
djsroknrol
Standard Member
Send Private Message

Guthrie, OK - USA

Vette(s):
1984 L83/MD8 coupe


Joined: 2/7/2011
Posts: 124

I've been getting around 16 - 19 in town and 19 - 23 on the highway. I'm convinced that the TB's are slightly off and I'm running on the rich side...my oldest son and his daughter are spending Fathers Day with us so I talked him into helping me check the base and balance out while they're visiting Wink


______________
Remember, there's no place like ~ ;)
Re: Average MPG in rural America? (8/18)
 6/18/14 12:19pm
mickvette
Standard Member
Send Private Message

, - United Kingdom

Vette(s):
1992 LT1 C4, got this in August 2013. My second Vette, previously owned a 79 C3, for 15 years.


Joined: 5/12/2014
Posts: 2

Mountaineer said: It may be due to the fact that it's an automatic,but It doesn't get such poor mileage that it prevents me from driving it ,but it would be nice if it got what everyone else seems to get.Premium is nearly $4.oo per gallon here,and it seem that ALL gas around here has that ethanol in it.

$4 a gallon, I wish Shocked. Here in the UK we pay (after converting £ to $) around $9 Cry, but I still rack up the mileage, guess we just love been scalped over here!



______________
Re: Average MPG in rural America? (9/18)
 6/19/14 8:55am
kjcoff
Standard Member
Send Private Message

Prospect, TN - USA

Vette(s):
94 LT-1


Joined: 9/6/2013
Posts: 12

Mountaineer, I'm in the backwoods of TN. My '94 is getting between 21-22 mpg going to and from town and right at 25 mpg when I head to the big city to say, watch the Titans fall in glorious defeat to any other team in the NFL! Here's a gas link I use when I'm out on the scooter to find the best gas available: http://pure-gas.org/extensions/map.html

|UPDATED|6/19/2014 5:55:05 AM (AZT)|/UPDATED|
Re: Average MPG in rural America? (10/18)
 6/19/14 12:06pm
Mountaineer
Standard Member
Send Private Message

Gay, WV - USA

Vette(s):
!989 Medium blue convertible


Joined: 4/14/2013
Posts: 11

My gas mileage has gotten a little better since I've switched gas stations.The man that I got the car from said that he only used BP,or Exon ,so that's all I ever ran,but one day the cashier at Krogers doubled my fuel savings points,and I decided to use them to fill the Vette up,and I gained about a mile per gallon on both the interstate,and the secondary roads.That's what I've been running lately,and it runs just fine.I don't even know what brand of gas it is,but I'm thinking it may have less additives,and more actual fuel per gallon,but that's just a guess. I have also discovered that running with the top down on the interstate cost me about a mile per gallon.
The reason that I use premium is that I figure the computer will turn down the timing if I use lower octain,and make it less efficient .I might be wrong about this assumption though.
I also would like to ask any of you that have gotten rid of your catalitic convertors ,but have kept your factory manifolds if you notice any difference on mileage,or power .My car is basicaly stock with the execption of flowmasters,and de-screening,and opening the air box.


|UPDATED|6/19/2014 9:06:28 AM (AZT)|/UPDATED|


______________
Re: Average MPG in rural America? (11/18)
 7/10/14 10:02am
hcbph
Standard Member
Send Private Message

Minneapolis, MN - USA

Vette(s):
Purchased a 1986 Convert August 2013, Bright Red color with a black top, it'd already received a Tremec 5 speed upgrade along with a disc upgrade prior to purchase.


Joined: 8/16/2013
Posts: 53

Been waiting to see if anyone more knowledgable than me would reply.
As I understand, most gas comes up the same pipelines regardless of what gas station is getting it.  The raw gas is all the same out of the same pipes and tanks.  As I understand it's when it's set to deliver that the corresponding additives are added to the gas for that particular brand or store.
I have 4 vehicles that all use 87 octane gas: Vette, T-Bird, F150 & Caravan.  Overall they all work well on BP, Shell & Holiday.  Next level is SA and Marathon.  I don't buy from no-name stations except in desperation situations (out of gas, it's 3 AM and nothing else open or available and probably on the road and don't know the area).
I get the best mileage overall from BP & Shell with Holiday a close 2d.  If I fill with SA or Marathon I can definitely see a decrease in gas mileage.  I have bought from Phillips 66 along with other brands in the past but most times it was because I was on the road and didn't find my preferred brands.
Because all my vehicles are stock relating to the engines etc, I use the grade the manufacturer recommends and have not had a problem with doing that in all the years I've been driving.
Another thing is most all my vehicles are pretty much mechanically stock.  Yes things like shocks or brakes may have been changed out but things like tire size, vehicle height, drivetrain related items are pretty much oem type items.  If you modify things like engine internals, tire width, diameter etc on them it can also have a negative effect on your mileage in addition to if you do stoplight racing or not.


|UPDATED|7/10/2014 7:02:34 AM (AZT)|/UPDATED|
Re: Average MPG in rural America? (12/18)
 7/10/14 10:17am
martone_1
Standard Member
Send Private Message

Fernandina, FL - USA

Vette(s):
1985 Corvette Coupe


Joined: 4/9/2012
Posts: 109

Anything over twenty is awsome! I would drive mine if it only got five miles per gallon I love it so much. when it comes to fuel there are way to many factors to consider. how clean are the tanks it is stored in how old is the fuel the additives that are used. the weather at the time you buy your fuel. to many to mention. the best way to choose is to shop around find one that works and stick with it. and drive your vette, enjoy the wind in your hair and let the sun shine always be at your back.
Re: Average MPG in rural America? (13/18)
 7/10/14 2:58pm
davep85c4
Former Member

Send Private Message

Joined: 4/4/2009
Posts: 254

My 85 in its trailer costs .31 cents a mile in Diesel fuel for the Super Duty to transport it to various venues around the western states where I take it out and drive it once I get there. Kind of like a trailer boat........ I put 10 gals of gas in the Corvette's tank about once a year.  I only drive it 100-150 miles a year, so I guess I get about 10-15 MPG the way I use/drive it.
Re: Average MPG in rural America? (14/18)
 7/10/14 5:37pm
davep85c4
Former Member

Send Private Message

Joined: 4/4/2009
Posts: 254

hcbph said:

Question - why are you putting premium in your Vette?  If you have the L98 as you said, it's unmodified then it should have 9.5-1 compression ratio.  That should run on 87 octane regular just fine.  You're not getting any benefit by running premium





I had this conversation with an Instructor at the GM training center in Burbank, back in 1985 shortly after I purchased my 85 new. Here was his reply:

"Sure, running regular won't hurt the engine, because the timing will be retarded if detonation occurs. But if the guy running next to you has premium in his tank, he may beat you because his engine will be producing more power, because his timing ISN'T as retarded as yours."

I've never forgotten that. And of course he's correct. Running premium may not be necessary to prevent detonation, but it certainly may be to derive the maximum potential performance.

Another thing to keep in mind is that "premium" back in the 80's was typically 94-97 RON, and "regular" was 91-94 RON.  Today "premium is 91, and regular is 87. Not to mention ethanol's "contribution". Todays "premium" isn't as good as "regular" was when the cars were new. Or, the gas today doesn't meet the specs of the gas the engine and tune were engineered to run on.

I haven't logged my 85 for performance for decades. (My Diacom laptop expired at least 10 years ago). But it would be an interesting study to log the differences in timing-retard between the two octanes in back-to-back comparisons where other conditions like ambient temps and the test-course could be somewhat controlled. My guess is that one could see the additional retard when using the lower octane.

The "benefit" one may receive by running higher octane in a vintage C4 is the better performance, drivability, and fuel economy that running with more timing advance than can be achieved with lower octane gives.


My .02





|UPDATED|7/10/2014 2:37:41 PM (AZT)|/UPDATED|
Re: Average MPG in rural America? (15/18)
 7/10/14 11:23pm
wingnut
Standard Member
Send Private Message

Naples, FL - USA

Vette(s):
1984 C4 Mild mods.85 fuelpump,Accel ignition, TCI, shiftkit, ramAir, Boshplat plugs, duels straight, VP 106 fuel mix, 1990 wheels,, Silver/Gray 1996 LT 4 Stock muffler eliminators Torch Red ZR1 Wheels


Joined: 6/19/2011
Posts: 46

Cool Just my $.02 I use only Sunoco 93 octane and mix it with C A M 2 fuel and I get 26  28 highway 19 20 in town. My comp. rto: 10.8 1 the motor knows the difference. Can feel it in the pedal . I think B P was American  Gas before white for marine use. Fuel comes in 5 gal cans and 55 gal barrels made by Sunoco for Nascar  I thinkThumbs Up

______________
Wingnut
 
Re: Average MPG in rural America? (16/18)
 7/11/14 3:13am
mickvette
Standard Member
Send Private Message

, - United Kingdom

Vette(s):
1992 LT1 C4, got this in August 2013. My second Vette, previously owned a 79 C3, for 15 years.


Joined: 5/12/2014
Posts: 2

Last week I had my best mpg yet, 30! This was on a 200 mile journey, mostly highways, averaging 80-90mph a lot of the time, very impressed, never got this on my old 79 C3!

______________
Re: Average MPG in rural America? (17/18)
 7/17/14 7:55pm
Mountaineer
Standard Member
Send Private Message

Gay, WV - USA

Vette(s):
!989 Medium blue convertible


Joined: 4/14/2013
Posts: 11

Do most of you find that you get better mileage with,or without cruise control.I use it nearly all the time on the interstate.If I set it to 70 on flat ground it climbs the hills effortlessly and maintains 70 precisely ,and usually only gains a mile or two going down steep hills .I think that I get better mileage with cruise because when I don't use it I catch my self running more in the fast lane,or speeding up to pass slower traffic.It can take a LONG time to pass a slightly slower car if you stay at a steady 70,and some times faster drivers don't like me hogging the passing lane.


______________
Re: Average MPG in rural America? (18/18)
 7/18/14 10:20am
hcbph
Standard Member
Send Private Message

Minneapolis, MN - USA

Vette(s):
Purchased a 1986 Convert August 2013, Bright Red color with a black top, it'd already received a Tremec 5 speed upgrade along with a disc upgrade prior to purchase.


Joined: 8/16/2013
Posts: 53

Mountaineer said: Do most of you find that you get better mileage with,or without cruise control.I use it nearly all the time on the interstate.If I set it to 70 on flat ground it climbs the hills effortlessly and maintains 70 precisely ,and usually only gains a mile or two going down steep hills .I think that I get better mileage with cruise because when I don't use it I catch my self running more in the fast lane,or speeding up to pass slower traffic.It can take a LONG time to pass a slightly slower car if you stay at a steady 70,and some times faster drivers don't like me hogging the passing lane.


Love Cruise Control, I've got it in all my vehicles and use it whenever I'm on the highway.  I can add to that a little info on the sweet spot (rpm wise) can have an effect your mileage.  Driving my truck (07 F150 extended cab heavy half, 8' box with 4.10 rear) if set it right in the sweet spot (2k rpms, about 62 mph) I've gotten over 20 mpg best out of it in the past.  If I go 65-70 I can plan on losing anywhere from 1-4 mpg out of it.  Going slower than 62 (as in say 55 mph) I will lose about 1 mpg.  This is all with the cruise on.  I've kept gas usage records for the last 5 years I've owned it to back it up.  Obviously it only does around 14-15 mpg in town.
In the Vette, so far it looks like about 1800 rpms (about 75 on the interstate) is the sweet spot, that's where I got the 32 mpg out of it on the highway with cruise.  60 mph is around 1600 rpms and I've gotten around 28-29 mpg in that again using cruise.  At 55 I get around 27-28 mpg out of it.
Cruise has saved me more than 1 ticket, just keeping it constant at the speed limit.  Red Vettes seem to attract police and highway patrol cars like flies to you-know-what.  Additionally cruise can maintain a constant speed in the best rpm range than I ever could manually so I use it whenever I can if on the highway.
 
Dave85C4 - I agree if you're racing etc you will have different needs than just driving, sorry I didn't make it more explicit that I was talking about driving in general, not racing.  I gave up racing over 40 years ago, back then it was SuperShell or Sunoco 260 but that was in high compression engines optimized for the drag strip (around 10.5 - 11 to 1 compression ratio).  If on the other hand you're just driving then I really don't see the need for higher octane fuel than the manufacturer recommends.  I haven't had an engine with a higher compression ratio than about 10-1 since the mid 70's so using high octane fuel buys me nothing other than draining my wallet a little quicker.  If I was still racing I'd agree but seeing I'm not I'll still stick by my statement on octane needs of current engines on the street (again excluding racing) really don't take higher octane rated fuel than the manufacturer recommends.


|UPDATED|7/18/2014 7:20:29 AM (AZT)|/UPDATED|
Our Sponsors help support C4VR