1996 850 Wagon Non-Turbo How to Maximize Gas Mileage?

[abscate]

Its horse crap. Of course, the 450 mpg carburetor was suppressed by the government - that was real.

ok, that was horse crap too.

[PeteB]

Mercedes' bionic car (at 0.19 Cd):
http://www.treehugger.com/cars/daimlerc ... t-car.html

[sleddriver]

My son bought his 850 a few years ago, has been putting about 2000 miles
per month on it, and constantly complains about the gas mileage

In addition to Stage 0, smoke test the intake system. I built a simple smoker recently and found several small vacuum leaks that I'd previously missed. Also, check the vacuum tree on the intake manifold. My caps were all hard-as-a-rock and leaking. I replaced them all with small lengths of silicone vacuum tubing, tied off on one end. Pull the tower off, and replace that o-ring. Mine was flattened and leaking. I used anerobic sealant (because I had it on hand) on the underside of the tower where it contacts the aluminum intake to ensure this joint was completely sealed.

Yet another vacuum line to check on an old Volvo is the one that connects to the brake booster.

After doing this, my MPG and performance both went up.

Smoke also finally helped me solve the dreaded P0455 GROSS EVAP code that plagued me for years.

[PeteB]

Thanks, great tips. Do you think that silicone sealer would work fine on the tower?
I think I'm going to buy some silicone vacuum tubing.
Do you have a link on how to build the smoke tester?

[sleddriver]

Not sure.
Search youtube. I built mine from an old aquarium pump, metal gallon paint can, some silicone hose and incense sticks for smoke. Simple, cheap & effective. Should have built one years ago. Sure would have saved me lots of troubleshooting time, not to mention gas when it was $3.75/ga. even in Texas!

[PeteB]

My parents have a 2006 V8 Cadillac DTS and they get 26 MPG on the highway at 70 MPH,
I would hope that the 850 can do a lot better.

[matthew1]

I see 30 MPG+ highway ... documented, sworn, notarized, reproducible every time without fail, in my 1997 854 turbo. I've lost track of how many times I've noted this... probably at least 50, and maybe 100 times.

I reset the MPG calculator after I've gotten up to speed on I-25. Calculated average, two-way runs, Denver to Castle Rock.

I do this week in and week out. I've seen 34 MPG, but that's an outlier. Normally I see 30-32.

[scot850]

My parents borrowed our 1993 850 GLT (NA/auto) and covered about 500km on highway and general driving on vacation. When we calculated it out is was just under 40mpg on a UK Gallon (4.5l = 1 gallon v's 3.8 in US).

Also a friend in the UK swore he regularly saw 37mpg in a NA 740 auto (again UK gallon).

Now my dad trained as a driver/chauffer in the army in the 50's so the key was keeping the car in motion, gentle acceleration and watching the speed. So smooth driving.

I had a fully loaded UK Vauxhall Carlton 3.0 GSi (1988 car and manual) and toured around Europe at 75-80mph and averaged 32mpg (UK gallon), so cars can do it if well maintained and driven smoothly. As for the high tire pressures, I'm sure they may help everything but tire wear as it will wear out the middle tread quickly.

Neil.

[scot850]

Again in Europe there are a lot of people who convert their cars to run on LPG. There LPG is 50-60% the coast of gasoline. You do loose some mpg, but performance is claimed to be the same, but in a mile/$ case you are saving a lot. Downside is cost to install can take up to 20k miles to recoup the cost.

Neil.

[PeteB]

He reports 376 miles/18 gallons or about 21 MPG almost all highway at 60 to 65,
obviously not good.

Not very good, he might have misread something so I'll have him try again.