454 engine

[pontiac east]

I'm looking at a 1996 crew cab with 69,ooo miles.  It looks great except that it has the 454 engine & I'm worried about the 12-13 MPG. around town.  Is this normal for this engine???????????? I didn't get a chance to see what axle is in it, yet!!  Any commets greatly appreciated!!!!!!!!!!

[Shaners]

I'm not sure, but I'm guessing the truck will probably have 4.10's or better, and 12-13 mpg's is about all it will get around town.  It might get 14-15 over the road....  The big thing is if you load it down, your milage won't suffer much.

doing the math of 13 vs 16 mpgs and 10k miles per year...

13 mpg =769 gallons

16 mpg = 625 gallons

This is a difference of 144 gallons/year

or 12 gallons per month

or 3 gallons per week...

it's not a big deal, when you break it down...

[NeXuS1]

at the 2500s with 454s we looked at most around 95, the owners said they could get around 15-17 if they drove like a really old guy. my dads new/used 2500 we picked up yesterday gets around 13 (so says the old owner). after my dad runs his truck some i'll let you know what his mileage is.

[Guest Friz]

That 454 mileage is just as good (or bad) as mine. I sure wish i had that power.

[Jpshostr]

Boy, I want to know how you guys are getting this mileage out of a 454.  Our 350 gets about 12 in daily driving, but the style of driving may be the kicker there.  I really find that 15-17 figure hard to believe though.  In my opinion, the gears in the rearend won't really make a noticeable difference in mileage with the deep overdrives today's trucks come with.

[NeXuS1]

well i dont really believe it my self. my 350 gets 12 if i'm lucky. but i have 35s and stock gearing and well i guess i dont drive like an old guy. like i said i'm waiting till he starts driving it to work.

[Pick]

My 2000 gets around 13.3 around town, if I go easy on the peddle. Towing 10,000 I get about 8.5 around town. Towing freeway I get 10.5. Never had it on an empty freeway trip. 6600 miles on truck. Using Mobil 1 10W30.

[GregP]

My 94 dualy with 454 got a consistant 10 mpg.  Mixed hwy/city commute of 45 miles a day each way.

350 Suburban gets 15 same duty cycle, a 50% improvement -Greg

[Mikeee]

Gas mileage !!!

 

I have a '99 crew dually automatic with stump pulling rear gears.

I get 9-10 mpg.

No matter if ...

empty or loaded

up hill or down hill

rain or shine

winter or summer

highway or local.

And that last 1/4 tank just absolutly disappears.

I have pumped in 2 more gallons of gas than the "manual" indicates as fuel capacity.

 

I paid $1.09 per gallon for regular yesterday.

[HendyPhoto]

If you want good gas mileage, buy a car, small truck or diesel.  you shouldnt really be buying a truck with that engine if you are worried about fuel economy!  You really wont get better than 15 no matter what engine or gearing you have.  Unless of course you get a diesel, and maybe a diesel would be a better route for you and fuel economy.

[C/K Man]

I have a '96 C-3500 reg. cab single rear wheel, L29, 4L80E and 4:11's.  It gets right around 12 in the city, 16 on the highway unloaded.  It's a bit worse with a load.

[99silveradoz71]

ah yes, the 454 and gas mileage...quite the contradiction in terms.  Had looked at a late 80's 454 that was in 1 of the Autotrader publications a few years back.  I thought it would've been perfect...reg cab, dually, 4x4...But mom called the guy and found out it got 10mpg...and needless to say, that idea was shot down as I was still in school at the time...but I've got my 99z71 now:)

[bstewart]

My '94 454 Suburban gets 7.5 mpg around town just like clock work!  (That's with the air on, I live in the hot area of the country.)  11-14 on the highway....

[Colorado Kid]

Read the topic title, I'm still laughing!

 

My '74 GMC 2WD 2500 with 454, TH-400 and 4.11 rear got 12 MPG in town and 12.5 at a steady 60 MPH.  It still got better than 10 MPG with a 4 horse trailer doing 75 MPH.

 

I also had a '78 Chevy 2WD C-20 with 350, TH-350 and 4.56 rear.  It never, ever, not even once got better than 11 MPG on a tank and usually was right at or below 10.0 MPG.

 

I drove it (the '78) from Colorado to Florida once (it was my only transportation at the time).  It had the two 20 gallon tanks and with the cruise set on 65 (as fast as I would run it...pretty wound up even then) it ran tanks dry like clockwork every 200 miles, plus or minus 1 mile.  

 

Given my experiance with the older carbureted non-overdrive trucks I think 12 city 16 hwy in a heavier (4WD, big cab) truck with more power sounds pretty good.  On the other hand those are the numbers my D-max makes pulling the 5th wheel.

[fortop]

I had a 73 Chevrolet 3/4 Ton long bed regular cab TH400 automatic and got anywhere from 7.5 to 11.0 mpg - almost all city driving.  I now have a 1984 Chevrolet 3/4 Ton with a 4 spd manual transmission and get the same gas mileage.  I think once you get into a 3/4 ton or heavier, the extra weight takes a big toll on gas mileage.  However, if you don't use he A/C, don't tow, and drive very cautiously, I think you could probably up your mileage to about 12-13, but that would be about the max, IMHO.  I tend to drive the pickup infrequently, so gas mileage is not a big issue for me.  I see guys with the new 6.0 engines reporting 10-13 mpg., so I don't think gas mileage has improved much with the new models. Also, the condition of the engine (especially tune up) makes a big difference on these big engines.