1990 Mercury Grand Marquis Station Wagon

[101Volts]

Whatever just happened, it looks like the fuel economy went up a bit with use over the last several tanks since the idling tank. It's a combination of that I used up the old "winter tank" gas and that I've just been using the car for long trips, and also (maybe?) that I just stuck some Iso-Heet in the fuel this last tank. I haven't filled up yet, though I can say the fuel economy (unless I now idle it away) is above 20 for this tank unlike the last two fill-ups. I haven't filled it back up yet.

Possible, still considered mods and ideas for future use:

Full Synthetic Fluids - ATF (Mercon V,) Power Steering Fluid (Which is ATF type F,) Engine Oil (0w30; May also use Archoil Friction Modifier) Gear Oil (75w90.)

These full synthetic fluids, I'm told, may indeed necessitate the use of a rebuild of both the engine and transmission which is why I haven't gone with them just yet. Got any suggestions, with 231.5k on the odometer? I think the odometer's a bit off though and reads higher than it is since the speedometer's 4 MPH too high at 55 MPH.

On-Demand Fan
Larger Tires

Also, to inspect and/or fix these:

Fan Shroud
Driver's Window (was acting up a bit though is closed now)
Inspect Suspension Bushings
Rust Bubbling Repairs (which there are a few to have removed and replaced with new metal and finish touch ups)
Speedometer Accuracy (reads +4 MPH too high as is)
Etc, Etc...

I'm going all out in my imagination, WITH a towing hitch. The previous owner did convert the A/C to R134, to speak a bit for his ownership of it.

[101Volts]

I read the manual; it says the car can run on 100% Gas, 90% Gas/10% Ethanol and even 5% methanol. Methanol isn't commonly sold here, so what do you think of adding some bottles of this HEET (Yellow Bottle) to each tank?



HEET (Yellow Bottle) is 99% Methanol. As I understand it, Methanol burns cleaner than gasoline. My tank is 18 gallons, so 5% is 0.9 gallons. Nine bottles = 108 ounces = 0.84375 Gallons. However, the HEET website doesn't recommend to use more than two bottles per 20 gallon tank of fuel. I can't imagine it takes into consideration my engine is actually designed for 5% methanol though, so now the question is: What else is there in this additive? Or, should I look for another source to get Methanol to put 0.9 gallons in per tank if it's cheaper? One Gallon = About $15.90 if I buy them individually, costs less in larger quantities.

I don't expect to be using 0.9 gallons in to start out, maybe half that. I don't want to knock out unburnt particles too fast and clog something.

[Frank Lee]

What is the goal?

[101Volts]

Originally Posted by Frank Lee

What is the goal?

It's part to make sure the fuel system is cleaned out for MPG increasement. Maybe nine bottles is a bit much, so one or two could do just fine. Just wondering if it's a useful option.

[Nonhog]

I don't get on here much as my Scion gets 33 MPG almost no matter how I drive.
I am sick of driving it, too much like a tin can, square one. I dream of a big quiet comfortable car like yours. In fact I had one and I swear the window sticker claimed 28 MPG? freeway of course. I never really drove it as I bought it for the engine/trans, and ended up using an Explorer engine trans for my project.
Anyway good luck - more power to you!

[cRiPpLe_rOoStEr]

Originally Posted by 101Volts

Maybe nine bottles is a bit much, so one or two could do just fine.

One or two bottles might be a rather conservative figure, targeted to econoboxes with smaller tanks, or to avoid damages to the fuel hoses when they're not rated for alcohol.

[101Volts]

Originally Posted by cRiPpLe_rOoStEr

One or two bottles might be a rather conservative figure, targeted to econoboxes with smaller tanks, or to avoid damages to the fuel hoses when they're not rated for alcohol.

Alright. The manual also states I can use up to 10% Ethanol, so no problem with it.

I may want to have a look at the Caprice though, being that it's a 1984 model I'm not sure it was designed to run on Ethanol without adjustments and the fuel lines being replaced.

[cRiPpLe_rOoStEr]

Originally Posted by 101Volts

I may want to have a look at the Caprice though, being that it's a 1984 model I'm not sure it was designed to run on Ethanol without adjustments and the fuel lines being replaced.

Though the small-block Chevy V8 is somewhat tolerant to alternative fuels, it's better to pay some special attention to the carburettor. Depending on which material is the float made out of, it may get degraded by the ethanol.

[101Volts]

Today, at 231,668 (approx.) on odometer I changed the differential oil to Amsoil Severe Gear 75w90. The old oil was noticeably thicker when cold than the Amsoil was, and I have no idea what the old oil was. No issues driving on this gear oil 50+ miles today. I should see some improvement.

[101Volts]

I'm probably not going to do much to this car; we've only driven it 3-4k miles since purchase in August 2014 and it'll never be a winter car as far as I can see. I'm never removing the roof rack, the most I can see changing (if I'll even bother) are these:

1: Electric Fan;

2: Pre-Heaters;

3: Custom Rear Wheel Skirting, must match the surrounding woodgrain;

4 Air Dam (although it's a stretch and I won't make it cheaply.)

It's too much of a showcar to do much but look pretty and be a pleasure to drive on the rare occasion I do drive it; I've had it in the garage every single day while it isn't driven.