Good Ol' 3800!

Discussion in 'GM' started by 99LeCouch, Feb 27, 2009.

  1. 99LeCouch

    99LeCouch Well-Known Member

    Managed to squeeze 31 mpg and 514 miles out of 16.6 gallons of fuel in my 1999 Buick LeSabre, with the 3.8l 3800 Series II V6. For this it got a tuneup. :bananajump:

    Most of this was highway doing about 60, yet 20% was purely in-town, stoplight-to-stoplight driving.

    What a great highway engine. Too bad GM killed it in favor of more complex, less-efficient designs. Sometimes you really can't improve upon a classic.
  2. kingcommute

    kingcommute Hypermiling Apprentice

    +1 on the 3800. A much better powerplant than those that replaced it. We had a 98 Intrigue that was a marvel on the highway. Didn't know about hypermiling back then, so our town mileage would always pull our averages way down, but on long trips it would shine.
  3. jkp1187

    jkp1187 Well-Known Member

    Totally. The old 3800 in my Impala is equaling the allegedly more fuel-efficient 3.5L in my wife's G6. The powerplant is bulletproof, and they should've kept it going.
    Last edited: Feb 27, 2009
  4. kingcommute

    kingcommute Hypermiling Apprentice

    and the Impala is a much smaller car - so not only is it kicking the 3.5L's ass from a displacement vs. displacement standpoint it is doing so with more mass to move around. and they killed it because supposedly consumers wanted more high-feature motors. Are there any GM products these days that still utilize that motor or its successor the 3.9?
  5. jkp1187

    jkp1187 Well-Known Member

    Didn't realize the 3.9L was the successor. I think the "base" level latest-generation Impala uses 3.9... And maybe the G6 GTP. But the latter is supposed to be tuned for sport, so the MPG probably won't be as good.
  6. kingcommute

    kingcommute Hypermiling Apprentice

    Looks like you can still get the 3.9 in the Buick LaCrosse, Lucerne, and Chevy Impala

    The 08 grand Prix uses it too in the base model and as you said the GXP version of the G6. The 3.6 Direct Injection has replaced it in most other applications it would seem.

    From what I've read on the 3.9 - they did a good job updating the 3800 - increased the power some, but didn't decrease the FE any.

    I blame Car and Driver - they were always taking pot-shots at the 3800. I think those auto-mags have some influence on the direction that manufacturers head. Do I have proof of this, no - its just my own personal theory.
  7. jkp1187

    jkp1187 Well-Known Member

    The chattering classes were always complaining about the lack of "refinement" in the old pushrod 3800.

    I don't see it. Compared to what? The 3800 feels smooth as can be in regular highway cruising, and whenever you need it to accelerate, there is sufficient power to get moving as fast as anyone would want to sanely drive. Again, relatively smooth delivery, too. (And if that wasn't enough, there was a supercharged application.)

    The 3.5L frankly sounds thrashy under load - almost like a 4 cyl. It doesn't like higher RPMs. It's nice to have the tiptronic-style shifter, true, but if you stay in 3rd gear and aren't totally gunning it, power gets inexplicably cut at a certain point. It must be the torque converter locking up, but it often happens at just the wrong moment (e.g., I'm trying to gain some speed prior to going up a hill.) I really have to pay attention to the tachometer to see the Impala's torque converter lock.

    The 3.5L is not awful, but as to whether or not it's an improvement...well, let's just say I'm skeptical.

    Oh -- and BTW, according to Edmunds, the '00 Impala LS and the '06 G6 GT are about the same curb weight. Impala is maybe ~40lbs. heavier. I was really surprised at that....they made a SMALLER car that weighed the same??!?
    Last edited: Feb 27, 2009
  8. jkp1187

    jkp1187 Well-Known Member

    The fact that they're STILL using it (despite the flack from the automotive press,) says a lot about its quality and utility. It's a workhorse powerplant.
  9. Taliesin

    Taliesin Well-Known Member

    The old Chevy 350 (5.7L?) from the early to mid 70's was another workhorse. I have had quite a few and getting 25+ out of a mid-size car (at that time, now it would be a large car weighing almost as much as a SUV) with a V8 engine was easy to do (don't ask, I was young and dumb at the time). Somehow they moved away from that and now their mid-size cars can't get that much.

    They attempted to downsize it to a 5.0L, but that was a waste. Less power, less reliable, and worse FE.
  10. phoebeisis

    phoebeisis Well-Known Member

    GMs pushrod V-8s get pretty good mpg when driven with FE in mind.
    My 1998 Suburban-5.7- 208,400 miles-gets 21.3 mpg on very long highway trips with the AC blasting to cool 150 cubic feet of cargo area. Granted 21 mpg isn't great, but considering it is carrying 3-4 passengers and maybe 800+ of other cargo, and the age and miles it is pretty good.
    I set the cc to 68 mph and otherwise stay under the speed limit, but not waaaaay under the limit.
    The more modern 5.3 Suburbans are at least 3 highway mpg better because of the motor,and slightly more aero shape.
    Driven 63 mph they(Suburbans-Tahoes) should be good for 25 mpg highway-about 5 mpg down on a minivan.They(2007 on) should approach 20 mpg city with motor on P&G and shutting down at redlights.
    They are pretty useful if you carry lots of people,animals,things. Not so useful if you drive alone most of the time.They are about 1500 lbs heavier than a midsized car, and a good 10-15 mpg down vs the car, so they are expensive to operate as a primary car(better to buy a cheap used one as backup/second car etc).
    The 3800 is a 3/4 varient of the SBCs more or less-tried and true. My 5.7 is very, very smooth and quiet.
  11. MaxxMPG

    MaxxMPG Hasta Lavista AAA-Vee Von't Be Bach

    The 3800 and 3900 are two different engines, although the 3900 replaced the 3800 in applications where the 3500 didn't quite meet the need.

    The 3800 is a 90 degree V6 and is the same old Buick 231 V6 that began life in 1962 as an iron version of the aluminum 215V8 with the back two cylinders lopped off. The stronger iron meant less metal was needed between the cylinders so they were able to increase the bore and get 225 cubic inches out of it. When it was resurrected in the 1970s to help meet CAFE they added a bit to the stroke and arrived at 3.8 liters.

    The 3900 is a 60 degree V6 and is a larger displacement version of the 3500, which itself is an evolution of the 2.8 liter V6 that rolled out in 1979 for the first time in the ill-fated X cars (Citation, etc). Because the block is so small and the bank angle so narrow, the 3900 is actually an "offset bore" design, where the centerline of cylinder bores do not intersect with the centerline of the crankshaft. The cylinders themselves were moved "outward" to make room for the larger cylinder bores.

    The 3800 is a Buick design which means it makes all the power at low revs. Wind it to the redline and it will moan and grumble and not make much more power. The auto mags love to bash that characteristic because it doesn't meet their vision of "sporty". But low end torque means the tach never needs to go above "2" in any normal driving.

    The 3500 is a Chevy design and is also a pushrod-style "all torque at low revs" powerplant. It will also buzz and grind if you push it to 6000, but that is not surprising considering the pushrod design and somewhat long piston stroke.

    Considering that the 3800 is 17 years older than the 3500/3900, the added fine tuning over the years made it a perfect "Buick" engine - silent at idle and with ample power for people who don't usually press their accelerator more than 1/4 inch. The 3900 is not a bad engine, but it will never reach the FE capabilities of the 3800. Even the newer 3600 HF V6 engine can't match the old iron 3800. Progress, indeed.
  12. ILAveo

    ILAveo Well-Known Member

    Many times "lack of refinement" is what people say about somebody else's car when they can't quite figure out why theirs cost more. I've noticed that BMW owners often use that phrase.;)
  13. 99LeCouch

    99LeCouch Well-Known Member

    Lack of refinement? Excuse me? My engine is nearly vibration-free despite having old, worn (stiffer) mounts and subframe bushings. I can barely feel the vibration through the steering wheel when the car is on. And cannot hear it at highway speeds except when going uphill. Plus it never feels strained to deliver its power when called upon. 5700 RPM does not sound or feel strained during the bi-annual Italian tuneup. It just has the most unique and lovely sound I've ever heard out of an engine.

    For an old fogey car this one gets around quite efficiently now that the nut between the wheel and seat has been adjusted. I love having gobs of torque available low in the rev range. Makes my in-town FE better. And don't have to use full throttle to do the exceedingly rare pass!

    Now on to 600+ miles per tank!
  14. jkp1187

    jkp1187 Well-Known Member

    I have to agree -- my 3800 sounds just great at the upper end of its rev-range. The 3.5L sounds like it's straining.
  15. ALS

    ALS Super Moderator Staff Member

    My mom has one in her 99 Park Ave (12,800 miles). That engine is sweet and when pushed runs like a bear. One of these days I'll have take her out on I-75 in SW Florida and see what she can do in the MPG department.
  16. 99LeCouch

    99LeCouch Well-Known Member

    31-33 with minimal techniques, 36 if you have a ScanGauge and keep between 60 and 65. Maybe 37 if you can go a whole tank on flat ground.

    The PA is a stretched LeSabre.
  17. scramblejim

    scramblejim I make Baked Beans

    The Impala is a bigger car than the G6. The Impala, Grand Prix, Century, Intrigue are all W platform cars. The Impala and newer Grand Prix use an aluminum subframe. The G6, 2004 and newer Malibu, Aura, are all Z platform cars. The H body cars are the LeSabre and Bonneville, and now the Lucerne. The C body car was the Park Ave.
  18. 98CRV

    98CRV Well-Known Member

    Nice job! Is that your best tank?
  19. 99LeCouch

    99LeCouch Well-Known Member

    It's my longest tank yet. I've come close to 500 miles a bunch of times. This time I got it!

    Have gotten better mileage on shorter distances, but that could have been skewed since the pumps weren't the same.
  20. 98CRV

    98CRV Well-Known Member

    Well that is just plain grand!:Banane02:

    Good work!

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