Legendary Mystery Buick 3.8, 27 mpg city (taxi), 44 mpg hwy (turbo)

[Cardinal Grammeter]

I'm trying to identify this "mystery" engine that Buick used during the last year or couple of years of the "3.8" before they went to the "3800."

These cars were not just those with 3.8's, but those with particular variants of the the 3.8 - identifying this engine sub-type was probably done by something like the color of the injectors "the one with the blue injectors and not the tan ones."

Taxi companies killed for these cars. My friend who owns a cab company discovered them by accident. The first one he bought, they put out in service in the afternoon. When the driver was done with his shift, my friend asked him how the new car was? He said everything was fine except that the "gas gauge did not work!"

Well, it did and the car was getting around 27 mpg being run by a local cab company.

There was another "resurface" of this car in the car mags during the test of a Grand National. They had the 5th wheel installed and on the freeway to the dragstrip, they were getting over 40 mpg - 44, I seem to recall.

Obviously, this was most likely the same mystery sub type.

So. Has anyone else ever encountered one of these 3.8s?

It would be nice to identify this variant and see what is involved to mod an ordinary 3.8 or 3800 into this trim. If possible.

[War_Wagon]

I used to know this stuff, but I am sure the 3.8 in the GNs was not the same engine used in the FWD Buicks of the time. They had a special crank, heads and pistons. There was also odd and even firing orders between the two I seem to remember. The last of the GNs/Turbo Regals was 1987, so if you are looking for a mystery motor, I would start looking pre-1988 as they would still have been called a 3.8L up to that point.

[theycallmeebryan]

Are you talking about the Buick Grand National/ T-type / Regal 3.8's? They made N/A versions of the motor with carburetors, but those were regular Regals. They are pretty efficient motors in stock form.

Mine's a turbo transplanted 1984 base regal, with lots of extra goodies .

[Cardinal Grammeter]

I'm referring to a pair of examples which are not the same engine.

The ordinary FWD Buick 3.8, and a road test of a Grand National. (I'm assuming the 44 mpg on the 5th wheel for the GN is far, far beyond the fuel economy of an common FWD Buick 3.8. My guess is that the common 3.8 gets 25-28 mpg hwy - maybe 30 at very best.)

[Phantom]

I think that it is just the normal 3.8 that was tuned had lower compression and a turbo. There are several people that get 38mpg highway with a 3800 and a supercharger, most of them get better mpg as they add power but only on the hw, city driving mpg nose dives. Look at pontiacbonnevilleclub or bonnevillepro one on them has a post on mpg.

[Cardinal Grammeter]

Haven't found those references yet...

But I did have a 1988 Olds Delta 88 with a 3800 and its best on the Turnpike from Pittsburgh to NJ was about 27 mpg. Around town was about 15 mpg.

How did the "mystery 3.8" do 27 city (as taxi) and the Grand National do 44 hyw on the way to the strip for the magazine article?

While I know for a fact that most 3.8's do 15-17 city, I'm guessing GN's do not typically do 44 hwy. If all variants did this, these would have been the most popular cars ever built. The fact that most people have never experienced this MPG performance suggests these variants were a very small percentage of all the 3.8's that were sold.

Some taxi business owner somewhere probably knows all about this. But if you think about it, you'd be a fool to tell anyone how to identify these engines since back in those days, these cars made a lot of profit for taxi companies. I was just hoping that they've been gone for so long, maybe someone will spill the beans...

[mcrews]

Sorry,

But 'legendary" ?????

Why is a taxi company runing a 2 door?

[Cardinal Grammeter]

"Two-door" ? What are you referring to?

Common 3.8's were placed in all kinds of 4-dr cars and the taxi companies used them whenever they found them. Both Buick and Olds. The Delta 88 and LeSabre were the preferred size. Which is not to say they did not run Cieras or Park Avenues if they found them cheap enough.

Seriously, a 3.8L 6-cyl that got around 27 mpg when in taxi cab service is not legendary in your book? I had a 1988 Olds Delta 88 3800 and got about 15-17 around down with some limited highway. That car was definitely not legendary and a gas hog in my book.

If you have some contradictory information or better examples of unusually good or poor fuel economy, please share them.

Regards,
Tom

PS. People seem to be having trouble realizing I am talking about two different 3.8 engines that exhibited extremely high fuel economy.

[Phantom]

I believe I found the link that I was referring to here View topic - Averaged 30 mpg! : PontiacBonnevilleClub.com the car that I was mentioning is owned by willwren.

The reason he mentioned two door is the GNs you mentioned to start the post is a two door.

The cars will handle much differently for city driving depending on the gearing and how it is driven. The mystery engine that you mention most likely was a manual trans with gearing optimised for low speed with one tall gear for the little bit of hw it gets.

[Cardinal Grammeter]

Thanks for the thread. It was interesting to see hwh mpg in the 30's, but these are "3800" engines and much newer cars than the mid-late 80's 3.8's.

Some people stated 17/27 which is pretty much what I got with my 88 Delta 88. I consider this typical fuel economy and would expect it to improve marginally 10-15 years later which was about where most of the cars were in that thread.

But there was not a single mention of anything above 40 mpg.

I'm going to have to find that road test of the GN where they said in the article that they got 44 mpg on the 5th wheel on the way to the strip.

As far as some kind of "manual transmission" optimized car, that pretty much has to be an impossibility. I cannot imagine a FWD Build LeSabre with a manual transmission. I mean, what would it be??? Any no sane cab company owner would ever buy a "stick shift!"

Its becoming clear that these high mileage variants were very rare since no one yet claims to know anything about them. It could very well be that they were part of a special Detroit experiment when they would put a limited number of "special cars" out in the market to see how they did.

What is the top GN site? There will be people that intimately know every road test of GNs that was ever published. Someone will surely remember that statement since it was so amazing.

(However, at the time I read it, I could have cared less since gas was cheap and the implications of high mileage meant absolutely nothing back then - it was a curiosity at best. Only after the advent of $4/gal gasoline and no advancements in modern car fuel economy, does that comment carry the weight that it should.)