(It Was) Mission Possible: A Boxy 1984 Caprice Classic
 

Update, September 5 2017: As of September 3rd my Father was driving home and someone started passing in a passing lane but did not relent and then Father swerved a bit to avoid him/her on a road with not much space on the side and hit a telephone pole; the car's done as far as our ownership's concerned.

I was upset that I didn't save it after the wreck; it looked repairable even if costly! A frame straightening, a new front end, a new radiator and maybe the engine would have started. I feel like I ruined something.

*Past edit was on 6th of March 2016.*

At the original posting time I didn't modify this car much, outside of maintenance the only things changed were driving habits.

Reason for using this car and Hypermiling with it is because we have it, we got it free and to inspire classic car folks who aren't familiar with hypermiling; To show they can increase fuel mileage even without driving like "Grandpa". I've also been inspired by Diesel Dave on here with his pickup.

Current (as of April 18 2016) stats:

A/C belt removed;
General Grabber HTS 225/70R15 Tires - I get approx. 2.2 extra miles per 100 shown on the odometer;
Pennzoil Platinum 5w30 Oil
Amsoil EaO59 Oil Filter
Amsoil Severe Gear 75w90 Gear Oil

Ideas:

Electric Fan;
Rear Wheel Skirting;
Synthetic or Biosynthetic Oil that stays in the 10-11 range (Pennzoil Platinum or Ultra Platinum 5w30, Renewable Lubricants 5w30, some Amsoil 5w30s are all a number of choices)
Synthetic Grease

Old photo:

http://i50.photobucket.com/albums/f3...ps8140057b.jpg

OK, Pennsylvania's 2014 Classic Car Riding Season has started. I know because I saw a Buick in a Burger King parking lot on the 6th of April.

So, What are some suggestions to modify this car? I'm asking for some quick mods. I already have the idle set a bit too low for when I first start the car, It's not so low that it shuts off at red lights but when I start it up for the first time in a day I sometimes need to start the car again because it shuts off.

Aerodynamically, How do some rear wheel skirts sound and what can I make them out of? I'd like to match the color of the paint too, This can go with a retro-car vibe too like on this 1970s Clamshell so I think it can be fun in that way too:

http://hooniverse.com/wp-content/upl...207-AM.bmp.jpg

(I do not own the 1970s Station Wagon pictured above. I added this note after the reply below this reply was posted.)

I'd like to A-B-A the skirts on the Caprice. I know it's a car without an OBD or OBDII port as it is now, But I can still A-B-A it on the highway if I go a set distance and speed per run.

I think an undercarriage pan (belly pan) would be of great benefit too; +1 MPG out of a car like this is valuable stuff. I'm not yet sure what it gets on highway trips but the last tank (373 miles rounded off) was close to 18.5 which is combined with little "city driving" and one 126 (Rounded off) mile trip that was mostly highway miles.

*edit here and below*

And now I realize this isn't the DIY forum, This is for posting what I'm doing to a car in, Yes?

Loose the roof rack for starters...

That's not the car I'm modifying here, I posted an image of a 1971-1976 era Clamshell Station Wagon in a comment about wheel well covers. But thank you for your insight.

This is the car in subject:

http://i50.photobucket.com/albums/f3...ps8140057b.jpg

Here's a mockup of a possible modification:

http://i50.photobucket.com/albums/f3...ps001cffa0.jpg

thatll look good. id drop it down even lower even with the bottom of the quarter panel and rocker. maybe add a stainless trip piece to match the ones on the bottom of the car.

what engine and trans are in it?

It has a 5.0 Litre Gas Engine and 4-Speed (Overdrive) Transmission so for its make and model year it gets the highest fuel economy out of the box compared to its other counterparts, Excluding the California model and Diesels, According to this page:

http://www.fueleconomy.gov/feg/bymod...aCaprice.shtml

14 City/16 Combined/20 Highway.

This car already stinks up the place a bit more than my Dad's Caravan but is it legal to remove the anti-pollution equipment on it and if I did would it raise the fuel economy? I live in an area of Pennsylvania that doesn't have pollutant tests done.

Thanks for the valuable information about lowering the car. I'm wondering though if that's a good idea considering some of the roads where I live and that I've scraped something (Maybe the tailpipe) on the road just going in and out of a particular parking lot. Is there something I can do about that?

A bit off-topic, Perhaps: Also I think for some cars like this one, Can EcoModder have a "Fuel economy information not available" option for when I log in trips in the Garage? I had to guesstimate all the fuel economy readings for the trips I did in this car so far.

And I used the aero template, Did I use it right?

http://i50.photobucket.com/albums/f3...ps9b21dae3.png

Oh I meant lower the fender skirt further than in the picture. Could lower the car itself but it's still a box and the undercarriage is very aerodynamically "dirty" some unseen aero mods could be air diverters to push air underneath the rear axle and the front lower control arms.

Ah. Well the car itself has wheel wells that curve inward, I'm sure I can work around that but that's the reason why I painted them only so far down. I like the thought of a belly pan on it too, When I drove it on I-80 I found it's draggier than Dad's Caravan.

Do you think it would get another 3 MPG even driving without EOCing if I stuck a Manual transmission in it?

(Also, I suggest to not rely on the spelling checker for proper spelling. I typed "Thin" instead of "Think"!)

Should check the Cadi and Pontiac versions of the same era. Many had skirt that could be adapted. This would give an OEM solution and look that could be built upon.


I wonder how hard it would be to swap the back glass to the aero coupe style?

http://www.powerful-cars.com/images/...e-coupe-13.jpg

Fyi, the 6.2 diesel is a fairly easy swap (bolts in, but normal diesel conversion stuff like brakes, tank...).

Hard to say how much a trans swap would be worth. It would def show an improvement

So are the Pontiac Parisienne and Cadillac Coupe De Ville models what you're referring to?

Here's a photo of a 1986 Pontiac Parisienne with wheel skirts:

http://www.curbsideclassic.com/wp-co...30-003-800.jpg

Maybe I can find some in decent shape in a junkyard.

And, What's involved in putting an aerodynamic glass on the back end? I'm aware the trunk will need to be shortened in such a modification.

As for the Diesel, Just for reference I realize you're talking about another motor and not the 5.7 that some of these G.M cars came with. An engine swap is definitely a possibility, But for now I'll use the stock motor. The car is close to 110k miles as is, I think I'd be able to get 23+ HWY if I stuck the right Diesel motor in though. And, I'm probably not going to tow anything with this car and it doesn't have a stock hitch.

Thanks.

Have you considered putting a TPI unit off an old F body on that old girl? They're probably giving them away right now. The 305ci version has small cross section runners that are long for more bottom end torque, and since you'll have complete control over the fuelling and ignition, you can tune that thing for max mpg. Then, of course, you could add some tri-y headers, small duals ( like 2.25" all the way out with catalysts, and an X or H pipe ).

A manual transmission does make a big difference if you EOC a lot, leaning a car of that vintage up (if you can) makes a bit of difference if done correctly.
Could check out the hundreds of dollars EFI systems floating around.

The diesels with a manual transmission (5speed variety) should top you out near 30mpg on the highway at low speeds. That is regardless of 5.7 or 6.2, also the 5.7 diesel can be reliable if proper precautions are taken, later goodwrench varieties could live a long time without even a fuel water separator, so one with a fuel water separator would likely be better.

Only benefit to the 5.7 over the 6.2 is if you get it free and because it drops in without motor mount work, beyond that it gets roughly the same FE (if your 6.2 if configured correctly) and is harder to adapt to a MT.

Cheers
Ryan

With a manual transmission and a Diesel you could see some 35MPG in highway :thumbup:

I think it would be awesome to get a car like that and put a 6.2 and manual transmission in!

I was trying to do the same thing with my boxy boat at one time. Just overall driving like an old man got me 23-25mpg. I had the computer read 28mpg at one time, but rush hour killed that quick.

Do you know what kind of ratio gears are in the rear? If you're cruising on the highway mostly, 2.73s or even 2.55s will do nicely with a 4 speed auto.

I had skirts on my Marq, but that was before I was worrying about gas mileage and they got ripped off after an accidental off-road adventure.
http://i74.photobucket.com/albums/i2...0LS/TCBPS7.jpg

6.2 is SBC mounts, and bellhousing. It will directly bolt up to what he has. They're dirt cheap as military drop out from the CUCV and HMMWV's. I've seen the come up several times on CL for 150-200 as complete drop outs. I almost went with a F-body 6.2/T-56 build instead of my VX.

OP- Not sure what's involved in the rear glass swap, never done it personally.

TBI is better at MPG than TPI. Smaller runners, and tuned for MPG.

I guarantee you the underside of that car is an aerodynamic nightmare. You could do a lot of aero upgrade down there without changing the outward appearance of the vehicle at all. Air dam to start, just to start saving a few bucks.

As others have said, rear skirts were a factory option. If you go a little crazy with homebrew and make yours smoother/bigger, well, most people won't even notice.

One wonders whether a grille block, on this monster, could even have a positive effect.

Upgrade the induction to the '89-and-up TBI. According to Wikipedia this was done for fuel economy purposes, but the EPA's numbers tell me it didn't work. Can't hurt though. It'll be a lot easier to tune for leaner operation.

Subscribed. I'd love to see someone crack 30mpg at cruising speed in one of these whales.

Another interesting option could be a Vortec 4800 out of an Express van. Or even the V6 wouldn't be the worst option at all...

I think they're 2.73s, Going by Automobile-Catalog.com.

I once had a grille block on this car but didn't check the economy while it was on since it wasn't driven much. The one tank I have logged in the Garage as of this post time is the first tank-to-tank measurement I ever got in this car, Before that we just did partial fill-ups.

I'm interested in the rear skirts and a belly pan. I'm also open to a Diesel with Manual Transmission conversion, But would like to do some other mods first and maybe get new tires; These things are probably 22 years old. (It sat in my grandmother's garage for a long time before we got it.)

Also, Here's a thought; Converting it into a hatchback for aerodynamic and storage purposes. Can I replace the rear seats with middle seats from a station wagon so they can be lowered for even more storage, Too? It's a thought, At least. I have the thought of adding a trailer hitch too, But I don't know what I'd tow with it.

And again, Would removing the pollutant controls from the car increase the economy? The car is already stinky upon start-up compared to newer cars, But I'm curious.

Also, I imagine I can add an air-bag system. And this car doesn't have cruise control as-is, I think that can be added too.

What is an induction system...?

*google search time*

Adding your own air bag system? I hope you mean for the suspension.

This is for the idea, It's visualizing:

http://i50.photobucket.com/albums/f3...ps3d6e3793.png

So I know I can convert it to Diesel with a Manual transmission, Add a belly pan and new tires; Plus, With Turning it into a hatchback and adding side skirts and smooth hubcaps and engine tuning and engine and transmission heaters and some headlight covers and Eco-driving I think I already have 30+ in theory. What a day.

Maybe a little changing of the hood to make that more aerodymaic will help too, So the wind breaks over the windshield a little easier?

I think a 20 gallon fuel tank (or smaller) for Diesel will suffice since the fuel economy is higher with Diesel and the fuel is heavier; With a smaller tank this may be a weight reduction.

Gee, What can a belly pan be made out of for under $100? I wonder, Is anyone on Craigslist is looking to get rid of a lot of Coroplast for free?

Not so sure if converting it into a hatchback would actually improve the aerodynamics...

Why? I meant for the steering wheel.

Huh. I wonder if it will or will not if done? I don't mean to make it into a station wagon, I can get one of those cheaply.

What are the revs like on the highway? With a strong V8 and travelling at lower speeds 55mph there could be some room to run skinnier tires all around and taller tires in the rear to lower final drive revs. Warm air intake, front air dam, wheel covers on the front, partial grill block, some belly pans maybe.

Just cutting the trunk away to turn it into a hatchback wouldn't be so aerodynamically-efficient as a Kammback.

Equipment-wise it doesn't have a gauge for the RPMs so how can I tell what the general neighborhood is - By ear? I think it sounds as if it's puttering along easily and well on the highway in overdrive. And I know people call some cars "Tired" if they're running poorly, I don't think the engine in this car is one of them though I'm not experienced with that yet at least.

Also, While riding this car on the highway at 60 MPH or higher the hood starts vibrating due to wind turbulence. Is that normal for these cars?

The odometer is accurate to a tenth of a mile too, And so I'm wondering if changing the tire size would effect this. I've heard that happens if someone put big enough tires on a car.

I didn't think of the WAI before, Thanks for that. What is involved? Maybe I should get a repair book for this car and remove the mud flaps? It seems the flaps scrape roads when pulling in or out frequently.

I think I should look into this a lot more than I have been if I want to get above 25 MPG in it while still using the gas engine. All my questions are revealing how little I know, Oh glory! :snail: I'm not bothered by it though, Questions show answers.

Oh. Well when I said "Hatchback" I meant modifying the whole body so it looks like it has a very long hatch on the back, Though in hindsight I think I'd make it shorter now; There would be a long bed behind the back seats and those rear seats would be changed to station wagon seats so they can be lowered for extra storage space and this would probably involve having a shop do it because the car would need painted again. That's what I was thinking at least, I didn't sketch it out and didn't think of how exactly I'd do it - It's just a theory so far.

Indeed. Just like some European midsize cars such as the Renault Laguna, Ford Mondeo, Opel Vectra (in this one the hatchback versions have the same lenght of the sedan ones), among many others.

I'm now in the market for some brand new tires. The ones that are on the car now, Are probably from 1992.

I'm thinking of getting some LRR tires, Maybe some of these Orange Peel tires?

http://ecomodder.com/forum/showthrea...eum-26530.html

However, I'd like to know the Rolling Resistance Coefficient of these tires; Is that public information?

I got a new battery in the car today too and am thinking of getting some engine heaters, Maybe this one included for the Gas engine while I have it:

http://www.amazon.com/Kats-13150-Alu...ng+tank+heater

Got suggestions for heaters?

Right on man. Love the car. I would think diff gears would be a big improvement for ya. Figure out what ratio you have an get the lowest possible.... ie lowest number:1 also I think your aero template is a bit off. I think the peak of the template should align to the peak or centre in your case, of your roof. Correct me if im wrong anyone..... GREAT project!!!

There is a really, really nice mid 80's Caprice at the car lot I drive by everyday. The window says it has 55k, working AC, power windows/locks (didn't know they were an option in the 80's Caprice), and V8.

I'm kind of considering getting it and dropping a diesel + manual into it. It looks like a brand new car. I'll be following your progress with great interest!

In this post there's not much to talk about as far as mods go. We got a new 5-year Battery in April. I'm getting a feel for the car with 35 Cold/39 Hot Tire Pressure with the stock tires and am gathering more data for tanks, I'm about 290 miles in to the current tank at this post time and have more miles to go before the tank is filled up and the car is inspected.

I was wondering, Are there any additives I should be using for this car since it has a carbureted engine? I use gas that has up to 10% Ethanol in it. I could use 100% Gas from a local gas station, However if it's the way it was a year or two ago it's still filthy; I was getting about 16 MPG on their pure gas one summer or spring day in the Caravan. I didn't even fill the tank up on it, I just put $5 or so of gas in! The lawnmower I tried to run on their pure gas wouldn't even run, Either. The lawnmower was very poorly maintained, But the point is when I used their E10 the mower ran compared to their pure gas which it wouldn't run on.

Here's a quote from the Orange Oil Tires Thread, Although I changed the quote a little bit for this thread:

I'm still looking for advice on tires and asked at the Chevrolet Forum too. Do the sizes I posted in this thread fit the car without modification to the car? I'm cross-checking beyond reading what's on Automobile-catalog.

I do see this is a popular car model for putting large rims on.

http://carphotos.cardomain.com/ride_...iginal.jpg?v=0

As for news on Boxy, We have a trickle-charger on it now which is a nice aid; I started the car on the first crank and I only pumped the gas three times before I cranked it. I removed the mud-flaps too.

I don't have experience upsizing tires, but the consensus around here is that it's usually cheaper and lighter to only upsize the sidewall height and keep the 15" wheels you have.

Also, here's an updated aero template for you--the key to lining it up is the roofline, which isn't actually so bad
http://ecomodder.com/forum/member-dk...price-aero.jpg

Man, that is a sweet ride. In very nice shape too, it looks like. There's something about the big, boxy, American sedans (and hilariously large two doors) of the '80s that sits very well with me.

Good luck on your hypermiling with it.

I'm still asking for help with the tire sizes. I posted on a Chevrolet Forum and hadn't received any replies:

Tire Size Questions for 1984 Caprice Classic Sedan - Chevrolet Forum - Chevy Enthusiasts Forums

Also, Now is time to figure out what engine heaters to use. I have a "Kat's 13150 1500 Watt Aluminum Circulating Tank Heater" in mind, Pictured below:

Amazon.com: Kat's 13150 1500 Watt Aluminum Circulating Tank Heater: Automotive

http://ecx.images-amazon.com/images/...L._SL1500_.jpg

What else can be used - I know about Transmission and Oil Pan Heaters but what else is there, If any?

As for Oil Pan and Transmission Heaters, I've heard these Kat's Pad Heaters work pretty well. What do you think of these?

Pictured below is the "Kat's 24250 250 Watt 4"x 5" Universal Hot Pad Heater."

http://www.amazon.com/Kats-24250-Watt-Universal-Heater/dp/B000I8XDFS/ref=sr_1_2?s=automotive&ie=UTF8&qid=1402611444&sr= 1-2&keywords=engine+pad+heater

http://ecx.images-amazon.com/images/I/41mNZZDyWbL.jpg

And I'm thinking, Higher than 25 MPG in this 1984 Chevy Caprice Classic Sedan? Yes we can. I'm also thinking of giving it a new dash cluster, Though not of this type which doesn't have Overdrive:

http://www.curbsideclassic.com/wp-co...5/HPIM1428.jpg

Gee, What's involved in something like this? These cars did come with vacuum gauges, As you can see on the far right in this photo. (The dash in the above photo is from a 1980 Caprice.)

It's been suggested that I override the air-pollution equipment on the car for higher fuel efficiency. Does this work? I don't have smog tests where I am now.

For tire size put on whatever fits and matches your load requirements, those cars like the buick roadmaster seemed to be flavor of the day tire sizes.

You could look in the manual or on the options placard usually in the glovebox to figure it out.

In the end on a v8 its probably a wash whatever size you throw on there, on ours its seemed to be 225/75r15's that fit nicely.


Also defeating the pollution equipment has basically no affect on fuel economy in your case. Main reason people do it is because they don't want to buy a cat.

The only way I could see a "Defeat" actually doing anything would be to figure out how to lean out the car and likely your emissions would be better afterword anyway.

Cheers
Ryan

How can the engine be leaned out? The Idle is lower than it was earlier (It was high, But not when this topic was created) and the car was harder to start and it would stall after it was first started it if the car wasn't given more gas. This was with the battery not being kept on a trickle-charger, Though. Speaking of which, Is there something that can cause excessive electrical use upon starting it? If it's not kept on a trickle-charger it's harder to start.

Also, This is a bit off-topic in hypermiling but how can the switch that turns on the dome light for the rear-right door be replaced? I tried removing it by un-screwing it but there isn't enough wire to pull it out far enough to replace it the way it is. Is it necessary to remove parts from the interior around the front-passenger's seat belt? I tried that too but there was something else in-between the wires and my hand.

Also on subject of the air-pollution reduction equipment, How can it be told if it needs to be replaced? The car is rather stinky upon start-up but is that due to the type of equipment used? Yes, The car is outside of an area with smog tests but it may not always be.

Question: 5w20 Full Synthetic Oil is already used in this car. Is an additive of aid such as the Lucas additive that makes oil even more slippery?

If 225/65R16 and 225/60R17 don't fit with the stock wheel wells what can be done to make them fit? Larger wheel wells?

Why not keep the cheap, abundant, reliable and fuel efficient 15" tires that come on the car stock?

In any event those tires probably do fit, a few simple measurements would verify it, but they would cost more and have little benefit otherwise.

If they did not fit you would need to expand your wheel wells, but more likely a few spring spacers or air shocks would accomplish the same thing depending on what way you are having trouble.

As toward lean burn that is usually quite involved on an O2 controlled car such as yours. There are methods of tuning your paticular year and there is also a wideband device that allows you to lean the mix manually once you get on the road.

Likely more cost than its worth though.

Cheers
Ryan