Was it all freeway?

Was it all freeway?

Yup, with cruise.

I kind of agree with 68 I don't think its possible to get 38 out a GM. In a Prizm, yes. GM no, I think maybe 28-29. The drag alone wouldn't allow it. Im not saying your math is wrong but something isn't right. Use a good map and see how long a stretch of road is and compare that with what your OD says. It might but off or you have too small of tires on it. This happened on the caprice the I had some really bald tires and I went on a road trip and received a mpg of 28 after new tires I did the same trip and averaged 24.5

I kind of agree with 68 I don't think its possible to get 38 out a GM. In a Prizm, yes. GM no, I think maybe 28-29. The drag alone wouldn't allow it. Im not saying your math is wrong but something isn't right. Use a good map and see how long a stretch of road is and compare that with what your OD says. It might but off or you have too small of tires on it. This happened on the caprice the I had some really bald tires and I went on a road trip and received a mpg of 28 after new tires I did the same trip and averaged 24.5

..more rotating mass and actually going faster.

..more rotating mass and actually going faster.

Not sure what you mean by that...

I set cruise at 75 always

But due to the new thread that added about an inch which is 2 more inches in diameter for the tire. The bigger the Tire the longer it takes to to rotate thus the odometer spins slower and speedometer shows a slower speed. How ever a smaller tire will make the wheel spin faster and thus allowing the odometer to spin faster and speedometer to show a faster speed than what the car is going. I hope that clears it up a little.

Not sure what you mean by that...

I set cruise at 75 always

But due to the new thread that added about an inch which is 2 more inches in diameter for the tire. The bigger the Tire the longer it takes to to rotate thus the odometer spins slower and speedometer shows a slower speed. How ever a smaller tire will make the wheel spin faster and thus allowing the odometer to spin faster and speedometer to show a faster speed than what the car is going. I hope that clears it up a little.

i was saying it in response to the "slick" to the new with the mpg. with the slick, yes the odo will be off, but i was saying that with smaller diameter, your car moves slower at any engine rpm vs a larger tire...making it easier for the engine...and the rotating mass of the tire being less. i wasn't factoring in the odo difference. it should be close to just going a little slower... sorta.

That 38 does seem really high.. I managed to see 27-28 mpg several times in my '87 Mustang GT (5.0) in 5th gear at 55 (back in the days of the 55 mpg speed limit). I've seen on the trip computer instant mileage in the range of 25 before in an '04-07 Grand Marquis rental cars, though.

28 mpg in a 5.0 Mustang with a 5-speed trans.? Sure, that's believable.

1. A unibody Fox body Mustang weighs about 1000 or maybe 1200 lbs. LESS than a BOF '90s Grand Marq.

2. '87 Mustang drag coef. < Gr.Marq drag.

3. Top gear (5th) in a 5.0 Mustang is WAY more efficient (lower RPM) than top gear in a FoMoCo automatic 4-speed

D.F. Geez, you seem to be taking my comments a bit personally.

Back on planet earth, neither Cobalt sedan LS rental cars or gently

used, mid-90s Grand Marq. get the kind of mileage you're claiming.

I get about a mile per 1000 calories.

DF if you're getting 38 MPG out of a 4.6 liter 2 ton boat like a GM and I'm getting under 20 in a V6 powered Riviera....something's not right here and I demand a recount! :angry2:

Edited September 26, 200817 yr by Delta Force79

I don't care if your odometer was just calibrated and Stephen Hawkings

did the math, use your head, 38+ mg did NOT really happen in that car.

I'm going to have to second (or like fifth now) that one:

http://www.fueleconomy.gov/Feg/noframes/10122.shtml

Read it and weep, DF:

16 City, 24 Highway, 19 Combined. That's what the manufacturer has filed WITH THE GOVERNMENT as being the car's official fuel economy. There's like a 5% margin of error depending on how much of an old lady you drive like, so best case scenario you're getting high 20's on the highway. And I seriously doubt it because I'll bet a million dollars you had the air conditioning on too.

38? Are you for real? So you mean to tell us that life for a Panther begins at a hundred-plus thousand miles because that's where they hit their sweet spot and DOUBLE their fuel economy? If that's the case then everybody in America needs to drive their vehicles to the junkyard IMMEDIATELY and all pick up a high mileage 15 year-old Crown Victoria/Grand Marquis/Town Car. Congratulations, you've found the answer! Hybrid technology is a sham! America will end its dependence on foreign oil by driving old beat-up Fords!

Here's a hint: don't take what the driver's information center tells you at the second you happen to glance down at it when you let your foot off the gas and coast down a hill as the car's overall fuel economy. If we all went by those figures then my mother's '85 Eldorado was getting 120 MPG..... but only when you were rolling up to a red light.

...everybody in America needs to drive their vehicles to the junkyard IMMEDIATELY and all pick up a high mileage 15 year-old Crown Victoria/Grand Marquis/Town Car. Congratulations, you've found the answer! Hybrid technology is a sham! America will end its dependence on foreign oil by driving old beat-up Fords!

Sweet... i received my $300.00 from the Junkyard for the RoadmOnster

this afternoon and am now styling in my 36.9 mile per gallon 1999 Ford

Interceptor, now if I over-inflate the bald tires, swiss-cheese all of the

non-essential inner sheet metal 1960s Gasser style and mount up some

back-up cameras in lieu of those bulky side view mirrors that rob the

car of several points of drag co.ef I'll be gettin' 40mpg in no time.

I just can't figure out how my old company car, a modern Town Car with

the same (but newer) 4.6 liter V8 only got 18-19mpg on the highway

even though I was driving for a limo company as an airport taxi & HAD to

drive like Mother Theresa for the sake of our rich/pampered clientele.

Both my B-bodies get about 14-16 in town and 23-24 highway. The Bonneville got 26 once but that was once. All the suns must have aligned that day.

Yup.... my beat -to-sh!t RoadmOnster is lucky to average anything above 18mpg.

& that's okay, considering my 2.4 liter I6/5-speed manual Datsun only averaged

22-25mpg being driven in the same manner. I'm okay paying $14 or so more to

keep the Buick fueled up, esp. since (God forbid) if a maniac in a BMW drives into

my B-body it will take the hit much better, and maybe I'll be able to avoid P.T.

and it is a FACT that FoMoCo transmissions are inferior to GM's TurboHydramatics

in terms of durability & fuel economy. Yes a B-bod or two driven by grampa at 55

for 200 miles on smooth highway has gotten 30 mpg... but western mass is not

flat like Florida, where DF was driving.

Considering mine arent as aerodynamic as your Roadmaster and dont have the benefit of fuel injection I would say I do well. I use mid grade fuel in them or the Bonnevilles 307 pings EVER so slightly. Transmissions in both though are from what mechanics tell me, especially the Bonneville pretty lightweight. Mine are both rebuilt though if that has anything to do with it. A/C use doesnt really affect either one.

My spotlights alone must rob the car of 1 mpg....

What are the spotlights for? Here they bust you for having those on a car if it isnt a police car. Hard to believe the Bonneville celebrated its 28th birthday this month. At least the door sticker says September of '80. The 1985 is in December. December of 1984 for that one.

It started as a joke.... they used to ride on top of SpeedingPenguins'

(you might remember him as the guy with the gray/silver '81 Malibu,

although he's never around here) 1988 Jeep Comanche 5-speed.

When he sold the truck he saved a bunch of stuff off of it and left it

in the barn I was renting at the time, later he told me to keep or

sell the stuff and so I said I'd make a 9C1 Roadmaster out of my '92

Buick... they're not swiveling spotlights but most people don't know

the difference anyway.

Of course I didn't expect anyone to really think my B-body with a

waterfall Buick grille is a Chevy Caprice or a cop car in general...

esp with the faded paint and all but since I also installed the larger

push bar style, "kustom, hand machined" bumperettes ($15 worth

of pipe & hardware from Home Depot) you'd be surprised how many

people move right out of the ("fast") passing lane and or yield to me.

Ive even had a few people ask if it was a cop car or ex-cruiser.

Ok. I just wonder about the weirdest stuff sometimes. Cool car though. I actually thought Buick did a little better with their version of this generation than Chevrolet did. Though I almost did get a 1993 Caprice. Maybe I should have.

Back in high school, 1993-1997, I used to think the Roadmaster sedan was

ugly, with it's narrow, plain, wide tail lights & what seemed to be an angry,

inverted mouth. Now I love those styling features, although I still would

love to own a Impala SS instead but for the money I paid for my '92 B-body

even a base Caprice would have been a steal.

The one thing that turns me off from some of the Roadmaster sedans is the

vinyl , padded 1/4 roof....it's cheesy and ugly & too grandpa for grandpa.

I'm glad I got a steel roof sedan, my old LT1 powered Roadmaster Estate

had more power and much better acceleration but I don't like the very

plain Jane grille on the estates. Oldsmoboi's phantom R-monster was a car

I had envisioned putting together for years!

And as far as the spotlights, your question was not stupid...

So there is quite a difference in power between the "old" 350 and the later LT1 350s used in the 1994-96 cars?

Edited October 1, 200817 yr by 2005 EquinoxLS

Yes... the LT1 is a more powerful motor.

BUT, not so much so that you should ever not buy a clean, straight '91-'93 B-body.

I kind of figured. I like the 1993 because they fixed the wheelwells but kept the 1991-1992 dash which I liked better than the 1994-1996 dash. If I did try to ever get one I would try to get a 350. Most though I think had the 305 just like the 1985 but with fuel injection. Still like FWD or AWD though for winter.

RWD is the safest driveline for winter.

All cars skid over black ice and stop with all four wheels.

Now as far as Caprice Classics, by the last gen. B-body

most of them were 350-powered although I was recently

tempted by 267 (4.3 liter SBC V8) economy Caprice that

was for sale at a buddy's used car lot.

OK....so back to fuel economy......

Drove a 2008 Escalade from Las Vegas down to Phoenix to deliver to a customer.........all freeway miles.......14.1mpg.

<ouch>

Now granted, the cruise was set at 85mph, and I had plenty of passing maneuvers in the mountains with my foot buried into the floorboard........(on the other hand, I've heard of 20mpg easily in the Escalade at a more relaxed 70-75mph cruise on a freeway stint....)

It's an Escalade, no shame at all getting 14mpg in a 6+ foot tall BOF Cadillac with a

honkin V8 and curb weight & luxury appointments that put Rolls Royce to shame.

BTW; here's a better pic. of those spotlights:

The Balt is up to 27.2 MPGs...about time!

The Balt is up to 27.2 MPGs...about time!

mostly city? mostly highway? mix?

RWD is the safest driveline for winter.

Remember I have driven RWD in winter quite a lot. But to each his own. Though the B-bodies are about the safest RWD winter vehicle there is based on my expeirience.

All cars skid over black ice and stop with all four wheels. True that.

Now as far as Caprice Classics, by the last gen. B-body

most of them were 350-powered although I was recently

tempted by 267 (4.3 liter SBC V8) economy Caprice that

was for sale at a buddy's used car lot.

Saw one of those too a little while back. There are actually more box B-bodies (1977-1990) than the later ones here. People didnt seem to like the 1991-1996 very much including my dad.

yeah.... I see their point too, I really love the '91-'96 Roadmasters but there's

something really cool about a '90 caprice with the flush mounted Headlights &

yet the BIG heavy chrome bumpers front and rear.

yeah.... I see their point too, I really love the '91-'96 Roadmasters but there's

something really cool about a '90 caprice with the flush mounted Headlights &

yet the BIG heavy chrome bumpers front and rear.

Damn straight. I think Dad would have traded the 1985 for a 1990 if one would have became available. But it never did. No matter. I love the 1985 to death. And the 1981.

Open the Attachment 68 and you will see the left front of the 1981 Bonneville.

That's a really nice Bonneville; why did I think it was a two-door? Did you ever have an older two-door car that you've mentioned here? I really could have sworn it was a two-door.

I had a 1981 2-door Caprice from 1993-1995. It wasnt nearly this nice though.

Dude, I'm quite shocked that you have not shown off this fine

Pontiac yet in the "members rides" forum. Not that I expected

it to be a beat up pile but that thing is gorgeous.

For everyone to look at here are more views of the 1981 Pontiac Bonneville.

And the 1985 Chevrolet Caprice.

This one is in even better shape than the Bonneville.

Dude, I'm quite shocked that you have not shown off this fine

Pontiac yet in the "members rides" forum. Not that I expected

it to be a beat up pile but that thing is gorgeous.

Only defects are that I have a little cauking in the body seam on each side going from the back window to the trunk. It leaks in the trunk a little in these spots. I shall do a better job with it when time permits. And the headliner is starting to come down though it is only a few small places. And it isnt coming down fast. Next Year that will hopefully be taken care of. The paint isnt real great but it is presentable enough that I will follow everybodys advice to leave it alone since other than the rear quarters it is origional. EVERYTHING works including as you can see by the condensation by the right front door the A/C The Vinyl top is perfect with NO bubbling underneath whatsoever. Even the door gaskets are in real good shape.

I suppose I have to download to a site to show off the 2 cars. Right?

A Chevrolet & Pontiac B-body:

That visor on the Caprice is phat!