Riv Performance
Would you like to react to this message? Create an account in a few clicks or log in to continue.

The 8th Gen Riviera Resource
 
HomeDashboardLatest imagesSearchRiviera Questions & AnswersWrite-Ups IndexRegisterRelated LinksLog in

 

 FAQ: Improving Bad Gas Mileage

Go down 
+38
charlieRobinson
denim
crzytrckr
Hometown Hero
Sir Psycho Sexy
LARRY70GS
NelsonBC12
Derek
brutusk1
RidzRiv
Fastbuick95
Abaddon
DEMonte1997
Rickw
Eldo
robotennis61
Robb
L67
jordynarz
97rivsc
mfmseadrift
TonySmooth89
albertj
deekster_caddy
Jason
Dj Brady
IBx1
Mr.Riviera
xxsupergman25xx
racinfan
AA
96riv
dreww
1998 Riv
CMan
Andysdorm
SpaceBar
Phoenix
42 posters
Go to page : Previous  1, 2, 3, 4, 5, 6, 7, 8  Next
AuthorMessage
L67
Aficionado



Name : Matt
Joined : 2007-06-05
Post Count : 1125
Merit : 37

FAQ: Improving Bad Gas Mileage - Page 3 Empty
PostSubject: Re: FAQ: Improving Bad Gas Mileage   FAQ: Improving Bad Gas Mileage - Page 3 EmptyFri Oct 23, 2009 2:56 pm

jordynarz wrote:
Yea I have a 95 razz It's been getting pretty poor gas mileage lately. like 13 or 14 in town. I replaced all the coil packs. and last year i replaced the plugs and wires. it has 121,000 miles on it. its a 1995 S/C.

You running premium?
Back to top Go down
jordynarz
Member
jordynarz


Age : 34
Location : Noth Bend oregon
Joined : 2008-06-22
Post Count : 59
Merit : 0

FAQ: Improving Bad Gas Mileage - Page 3 Empty
PostSubject: Re: FAQ: Improving Bad Gas Mileage   FAQ: Improving Bad Gas Mileage - Page 3 EmptyFri Oct 23, 2009 2:58 pm

L67 wrote:
jordynarz wrote:
Yea I have a 95 razz It's been getting pretty poor gas mileage lately. like 13 or 14 in town. I replaced all the coil packs. and last year i replaced the plugs and wires. it has 121,000 miles on it. its a 1995 S/C.

You running premium?


Yup I am running premium. I always go to Chevron lol.
Back to top Go down
L67
Aficionado



Name : Matt
Joined : 2007-06-05
Post Count : 1125
Merit : 37

FAQ: Improving Bad Gas Mileage - Page 3 Empty
PostSubject: Re: FAQ: Improving Bad Gas Mileage   FAQ: Improving Bad Gas Mileage - Page 3 EmptyFri Oct 23, 2009 3:04 pm

jordynarz wrote:
L67 wrote:
jordynarz wrote:
Yea I have a 95 razz It's been getting pretty poor gas mileage lately. like 13 or 14 in town. I replaced all the coil packs. and last year i replaced the plugs and wires. it has 121,000 miles on it. its a 1995 S/C.

You running premium?


Yup I am running premium. I always go to Chevron lol.

Service Engine Soon light on?
Back to top Go down
xxsupergman25xx
Aficionado
xxsupergman25xx


Name : Scotty
Age : 37
Location : Pittsburgh, PA
Joined : 2007-03-03
Post Count : 1251
Merit : 13

FAQ: Improving Bad Gas Mileage - Page 3 Empty
PostSubject: Re: FAQ: Improving Bad Gas Mileage   FAQ: Improving Bad Gas Mileage - Page 3 EmptyFri Oct 23, 2009 6:12 pm

im pretty much the same as u.
i run 93, everything is clean inside and out...
what im narrowing mine down to is a crracked exhaust manifold. run the seafoam and u can see if a bunch of smoke comes out the front.
Back to top Go down
http://bodyspace.bodybuilding.com/xxsupergman25xx/
Robb
Amateur



Name : Robb
Age : 47
Location : Batavia, NY
Joined : 2010-07-12
Post Count : 26
Merit : 0

FAQ: Improving Bad Gas Mileage - Page 3 Empty
PostSubject: Re: FAQ: Improving Bad Gas Mileage   FAQ: Improving Bad Gas Mileage - Page 3 EmptySun Jul 25, 2010 3:31 pm

I'm resurrecting this thread because I'm in the same boat as supergman. I'm getting 16 mpg on a tank. Same year, mods, and color even. So what did you find? My engine bay is loud, so I know I need a new dougnut, maybe new exhaust gaskets. I will be checking the plugs and putting seafoam in the tank soon. I just ordered an air charge sensor too, as mine is broken and had tape wrapped around it, does that affect mpg? I have already run seafoam through the intake. Is there a way to check the O2 sensor with a multimeter?
Back to top Go down
robotennis61
Guru
robotennis61


Name : robotennis
Age : 63
Location : las vegas
Joined : 2007-12-17
Post Count : 5562
Merit : 143

FAQ: Improving Bad Gas Mileage - Page 3 Empty
PostSubject: Re: FAQ: Improving Bad Gas Mileage   FAQ: Improving Bad Gas Mileage - Page 3 EmptySun Jul 25, 2010 4:07 pm

ok,but just a WOA,check to make sure your cat aint clogged before you do the seafoam thing.
on another note.do the obvious. change the fuel filter,clean the AIC valve.clean the PCV valve.clean the throttle body.clean the MAF.check all vac lines. u can clean the EGR valve while your at it too. ive been told a clean one helps.
Back to top Go down
Eldo
Expert
Eldo


Name : Mark
Age : 59
Location : West Salem, Oregon... FINALLY
Joined : 2009-04-09
Post Count : 3174
Merit : 104

FAQ: Improving Bad Gas Mileage - Page 3 Empty
PostSubject: Re: FAQ: Improving Bad Gas Mileage   FAQ: Improving Bad Gas Mileage - Page 3 EmptySun Jul 25, 2010 7:50 pm

Robb wrote:
I'm resurrecting this thread because I'm in the same boat as supergman. I'm getting 16 mpg on a tank.

What kind of driving?
Unless I take a trip (and get 27 MPG) I drive lots of short, cold-start, stop & go trips and all I've ever gotten is 16 MPG...
Back to top Go down
deekster_caddy
Master



Name : Derek
Age : 52
Location : Reading, MA
Joined : 2007-01-31
Post Count : 7717
Merit : 109

FAQ: Improving Bad Gas Mileage - Page 3 Empty
PostSubject: Re: FAQ: Improving Bad Gas Mileage   FAQ: Improving Bad Gas Mileage - Page 3 EmptySun Jul 25, 2010 9:31 pm

Robb fix all exhaust leaks before any further troubleshooting.
Back to top Go down
Robb
Amateur



Name : Robb
Age : 47
Location : Batavia, NY
Joined : 2010-07-12
Post Count : 26
Merit : 0

FAQ: Improving Bad Gas Mileage - Page 3 Empty
PostSubject: Re: FAQ: Improving Bad Gas Mileage   FAQ: Improving Bad Gas Mileage - Page 3 EmptyMon Jul 26, 2010 2:59 pm

Ok, so I found out I have an intake leak somewhere on the bottom of where the TB attaches to the SC, AND an exhaust leak somewhere in the header after the collector. So, I'm going to get a TB gasket today and put that in. Headers may have to wait unfortunately. Anyone have any used headers? I also found I have Delco platinums in the car that are slightly used, like .005" more gap. Is it better to keep these or go with Autolite coppers for mileage?
Back to top Go down
Eldo
Expert
Eldo


Name : Mark
Age : 59
Location : West Salem, Oregon... FINALLY
Joined : 2009-04-09
Post Count : 3174
Merit : 104

FAQ: Improving Bad Gas Mileage - Page 3 Empty
PostSubject: Re: FAQ: Improving Bad Gas Mileage   FAQ: Improving Bad Gas Mileage - Page 3 EmptyMon Jul 26, 2010 3:36 pm

Well, a TB leak would certainly F things up... As for the plugs, if your motor is stock, don't throw away the platinums, just re-gap them.
Back to top Go down
Rickw
Guru



Name : Rick
Location : Lancaster, MA
Joined : 2008-09-13
Post Count : 6282
Merit : 119

FAQ: Improving Bad Gas Mileage - Page 3 Empty
PostSubject: Re: FAQ: Improving Bad Gas Mileage   FAQ: Improving Bad Gas Mileage - Page 3 EmptyMon Jul 26, 2010 4:10 pm

Robb wrote:
Ok, so I found out I have an intake leak somewhere on the bottom of where the TB attaches to the SC, AND an exhaust leak somewhere in the header after the collector. So, I'm going to get a TB gasket today and put that in. Headers may have to wait unfortunately. Anyone have any used headers? I also found I have Delco platinums in the car that are slightly used, like .005" more gap. Is it better to keep these or go with Autolite coppers for mileage?
Robb, if you don't fill out your signature and post it with at least what year car you have, how would anyone know if they have a spare set of exhaust manifolds for you.
You are running manifolds aren't you or do you have Headers installed.?????

If you are indeed using the term Collector correctly, then that would be aft of the header and need welding anyway.
You have to be more specific or use the correct terminology to be helped by anyone.

FIRST a SIGNATURE, or no more answers for you....FAQ: Improving Bad Gas Mileage - Page 3 Icon_razz
Back to top Go down
Robb
Amateur



Name : Robb
Age : 47
Location : Batavia, NY
Joined : 2010-07-12
Post Count : 26
Merit : 0

FAQ: Improving Bad Gas Mileage - Page 3 Empty
PostSubject: Re: FAQ: Improving Bad Gas Mileage   FAQ: Improving Bad Gas Mileage - Page 3 EmptyMon Jul 26, 2010 4:50 pm

I just did my signature, sorry. Its a 95 SC. The stock manifolds are welded headers right? This is my first 3.8, so I'm not sure what they came with stock, but I definitely have mandrel bent welded headers. I usually think of manifolds as cast iron. Here is a pic of what's on my car.
FAQ: Improving Bad Gas Mileage - Page 3 G:\BlackBerry\pictures\IMG00195
Back to top Go down
Rickw
Guru



Name : Rick
Location : Lancaster, MA
Joined : 2008-09-13
Post Count : 6282
Merit : 119

FAQ: Improving Bad Gas Mileage - Page 3 Empty
PostSubject: Re: FAQ: Improving Bad Gas Mileage   FAQ: Improving Bad Gas Mileage - Page 3 EmptyMon Jul 26, 2010 5:00 pm

I still see no Signature nor any Pic's.

Sorry can not help you, nor can anyone else.
Back to top Go down
deekster_caddy
Master



Name : Derek
Age : 52
Location : Reading, MA
Joined : 2007-01-31
Post Count : 7717
Merit : 109

FAQ: Improving Bad Gas Mileage - Page 3 Empty
PostSubject: Re: FAQ: Improving Bad Gas Mileage   FAQ: Improving Bad Gas Mileage - Page 3 EmptyMon Jul 26, 2010 5:05 pm

Robb go into your user preferences and enable the signature.

95 SC had a series I 3800, whose stock manifolds closely resemble headers. They are tubular pipes and not cast iron.
Back to top Go down
Rickw
Guru



Name : Rick
Location : Lancaster, MA
Joined : 2008-09-13
Post Count : 6282
Merit : 119

FAQ: Improving Bad Gas Mileage - Page 3 Empty
PostSubject: Re: FAQ: Improving Bad Gas Mileage   FAQ: Improving Bad Gas Mileage - Page 3 EmptyMon Jul 26, 2010 5:50 pm

Robb,
With a 95 and the way your manifolds or headers are made, you are much better off bringing it to an custom exhaust shop and have the stock headers welded up tight.
The only reason I say a custom exhaust shop is they usually have very good welders on staff.
You will need to determine that for yourself, or if you know someone that can do a good job.
Remember they are only so thick, so chose your welder carefully.
Finding a good used set may be a challenge.
Back to top Go down
Robb
Amateur



Name : Robb
Age : 47
Location : Batavia, NY
Joined : 2010-07-12
Post Count : 26
Merit : 0

FAQ: Improving Bad Gas Mileage - Page 3 Empty
PostSubject: Re: FAQ: Improving Bad Gas Mileage   FAQ: Improving Bad Gas Mileage - Page 3 EmptyMon Jul 26, 2010 6:08 pm

Ok, changed it so people can see my sig. Sorry, didn't know I had to do that, I'm a noob on here. I got other pics to upload, I don't know why this one won't. Anyway, its already been answered.

I have what I would call stock headers, but I'll call them manifolds for simplicity. I will just get these welded, unless someone has a stock or aftermarket set cheap. I actually have a shop that is amazing at exhaust, and they're cheap. The biggest problem is going to be getting them off because its my only daily driver. I'm going to do some more reading to understand what I need to do better.
Back to top Go down
Rickw
Guru



Name : Rick
Location : Lancaster, MA
Joined : 2008-09-13
Post Count : 6282
Merit : 119

FAQ: Improving Bad Gas Mileage - Page 3 Empty
PostSubject: Re: FAQ: Improving Bad Gas Mileage   FAQ: Improving Bad Gas Mileage - Page 3 EmptyMon Jul 26, 2010 6:15 pm

Nobody, or should i say, no company makes headers for the 95 that i know of.
That engine is unique unto itself.
If you can find a used set to replace yours with, or a used set that also needs welding, you will be able to do the swap when not needing the car hopefully.

As with any exhaust system, there are always other connections and joints that need to be considered when doing an R&R.

Maybe someone that has done a 95 can chime in.

I know there is a lot of info on here that helped me prepare for the Manifold to Header swap on my 98, but they are totally different than the 95. Sorry.


Last edited by Rickw on Mon Jul 26, 2010 6:22 pm; edited 1 time in total
Back to top Go down
Robb
Amateur



Name : Robb
Age : 47
Location : Batavia, NY
Joined : 2010-07-12
Post Count : 26
Merit : 0

FAQ: Improving Bad Gas Mileage - Page 3 Empty
PostSubject: Re: FAQ: Improving Bad Gas Mileage   FAQ: Improving Bad Gas Mileage - Page 3 EmptyMon Jul 26, 2010 6:20 pm

Wow, I had the chance to get this one or a 98 and the guy with the 98 didn't get back to me so I went with this 95. Seems like a 95 Riv is an odd duck for a lot of things. Oh well, anyone want to trade?
Back to top Go down
Robb
Amateur



Name : Robb
Age : 47
Location : Batavia, NY
Joined : 2010-07-12
Post Count : 26
Merit : 0

FAQ: Improving Bad Gas Mileage - Page 3 Empty
PostSubject: Re: FAQ: Improving Bad Gas Mileage   FAQ: Improving Bad Gas Mileage - Page 3 EmptyMon Jul 26, 2010 6:47 pm

Ok, thanks Rick. I'm only going to need the manifold gaskets and a doughnut I think, they PO replaced the entire manifold back exhaust. I actually got off the phone with a guy that has a parts 95 SC thats 45 min away from me, and said he can scan my car FTW. I just have to figure out if I want to have yet another car to work on.....
Back to top Go down
robotennis61
Guru
robotennis61


Name : robotennis
Age : 63
Location : las vegas
Joined : 2007-12-17
Post Count : 5562
Merit : 143

FAQ: Improving Bad Gas Mileage - Page 3 Empty
PostSubject: Re: FAQ: Improving Bad Gas Mileage   FAQ: Improving Bad Gas Mileage - Page 3 EmptyMon Jul 26, 2010 7:21 pm

dont give up buddy. the 95 has her charms too. sinister perf. can customize a chip for u,a few xtra ponies.
Back to top Go down
Robb
Amateur



Name : Robb
Age : 47
Location : Batavia, NY
Joined : 2010-07-12
Post Count : 26
Merit : 0

FAQ: Improving Bad Gas Mileage - Page 3 Empty
PostSubject: Re: FAQ: Improving Bad Gas Mileage   FAQ: Improving Bad Gas Mileage - Page 3 EmptyThu Jul 29, 2010 11:49 am

Ok, so I have 2 leaks on the TB. Is there a replacement for the metal heat pipe that goes from the exhaust to the SC? Mine has a crack in it. Do you need this or could I just block it off? I have a lot of aluminum flashing that could work goo for that. Thanks.
Back to top Go down
DEMonte1997
Aficionado
DEMonte1997


Name : Rick
Age : 46
Location : CT
Joined : 2009-03-03
Post Count : 1429
Merit : 37

FAQ: Improving Bad Gas Mileage - Page 3 Empty
PostSubject: Re: FAQ: Improving Bad Gas Mileage   FAQ: Improving Bad Gas Mileage - Page 3 EmptyThu Dec 23, 2010 12:47 am

My car's gas mileage has plummeted recently but I realized that I've been only doing city driving for the most part. Couple that with holiday traffic... YUCK. I need to calculate how bad the mileage is next fill up. Right now my gauge is a couple ticks under half full and the trip says 185 miles. That seems ridic low. frown
Back to top Go down
Eldo
Expert
Eldo


Name : Mark
Age : 59
Location : West Salem, Oregon... FINALLY
Joined : 2009-04-09
Post Count : 3174
Merit : 104

FAQ: Improving Bad Gas Mileage - Page 3 Empty
PostSubject: Re: FAQ: Improving Bad Gas Mileage   FAQ: Improving Bad Gas Mileage - Page 3 EmptyThu Dec 23, 2010 12:56 am

I typically drive pure city driving, with lots of cold starts, and only the occasional 10-mile highway run...
I get 16MPG that way, but 27+ on a 'pure' highway run.
Back to top Go down
DEMonte1997
Aficionado
DEMonte1997


Name : Rick
Age : 46
Location : CT
Joined : 2009-03-03
Post Count : 1429
Merit : 37

FAQ: Improving Bad Gas Mileage - Page 3 Empty
PostSubject: Re: FAQ: Improving Bad Gas Mileage   FAQ: Improving Bad Gas Mileage - Page 3 EmptyThu Dec 23, 2010 9:54 am

I think I'm right about where you are for my mileage. Will find out in a few days when I fill up again. These cars get awesome highway gas mileage but around town driving kills them even when you stay out of the gas.. frown Guess the same could be said for any car though unless it was a very small compact or hybrid. smile
Back to top Go down
Abaddon
Expert
Abaddon


Name : Scott
Location : Macomb, Michigan
Joined : 2010-02-24
Post Count : 4314
Merit : 185

FAQ: Improving Bad Gas Mileage - Page 3 Empty
PostSubject: Re: FAQ: Improving Bad Gas Mileage   FAQ: Improving Bad Gas Mileage - Page 3 EmptyThu Dec 23, 2010 9:58 am

Yeah, I've noticed that my tune doesn't like the cold weather. Well, actually it loves the cold weather lol. But I have noticed a significant MPG drop since the climate change. All my driving is city. Not very fun to watch the fuel gauge drop......
Back to top Go down
Sponsored content





FAQ: Improving Bad Gas Mileage - Page 3 Empty
PostSubject: Re: FAQ: Improving Bad Gas Mileage   FAQ: Improving Bad Gas Mileage - Page 3 Empty

Back to top Go down
 
FAQ: Improving Bad Gas Mileage
Back to top 
Page 3 of 8Go to page : Previous  1, 2, 3, 4, 5, 6, 7, 8  Next
 Similar topics
-
» Unexplained MPG increase
» MOSTLY good oil report analysis (Blackstone Labs)
» Where is mileage recorded, in ECU/PCM?
» FAQ: High Mile Club - Wear/Repair Reports
» Here's a low mileage Riv for sale on ebay

Permissions in this forum:You cannot reply to topics in this forum
Riv Performance ::   General Tech :: Care & Maintenance-
Jump to: