Herman and Operation 30MPG

[callahanoffroad]

A few updates and an update to the repair list:

So far he's gotten:
new plugs,
wires,
cap,
rotor,
ignition coil,
brakes,
shocks,
struts,
sway bar end links,
dash pad,
pcv,
air filter,
poly upper and lower torque mounts,
right hub,
radiator,
radiator hoses,
shimmed the AC,
new ebrake cables,
New ebrake pads
timing belt,
water pump,
Heater core
Ignition switch
Repaired the VVIS
New oil filler gasket
Fresh coolant
New rear speakers
New tires
New vacuum lines
New battery

So far I'd estimate I'm about $4k in.

I repaired VVIS yesterday and boy is there a difference in driving the car! Before the power band would be nearly nothing between 1k-4k rpms, at 4k the car would start rapidly accelerating like a turbo had kicked in. Now it is a consistent and smoother power band through all of acceleration. Is it a turbo? No. But is it much better to drive around town? Yes.

Noticed smoke coming from the dipstick again yesterday. Looks like I get to redo the pcv system. Gotta wait for a garage for that one. I intend to do a compression test and leakdown test as well once I get access to a garage. Hopefully July.

I'm debating a head rebuild. It's at about 192,000 right now. I'm not sure if I should grab a 2nd head and rebuild that or pull the head on my car and take a few days off work. It's my only car so I'm leaning towards grabbing a second head and rebuilding it off of the car. I think a head rebuild should be done by 250,000 miles on these 850's. While I'm in there I'll do timing belt, water pump, plugs, and air filter. All of which is due at 210,000 anyways.

Thoughts are appreciated.

[callahanoffroad]

27.5 on the highway in the winter should be about right for an 850.
http://ecomodder.com/forum/tool-aero-ro ... ep=40-65-1.

Documented figures for an 850 (scroll to bottom):
http://ecomodder.com/wiki/index.php/Veh ... _Drag_List

You want to tweak the figures so that the CDa displayed after submitting the query matches what is known for the vehicle. There is some educated guesswork involved for sake of simple 'is observed mileage in your car in the neighborhood' you tweak the CD figure (I used .323 instead of .32). Engine efficiency is tweaked down from the default to account for increased blowby on an older high mileage vehicle, drivetrain efficiency and electrical parasitic loads are educated guesses that might be typical for a 90's-something vehicle.

If you set the calculator for summer fuel and ambient temperature it hikes to around 30mpg at 60mph.

I just got to play with this today, and boy is that a fun tool! almost as much fun as my effective compression ratio calculator tool that I for no apparent reason like to use to see how high of boost you can run at varying compression ratios. So thank you for posting that!

[callahanoffroad]

Okay, just realized it's been a month since I updated last. No major repairs. It's been over 80 degrees F here for at least a month now. My mileage slowly creeped down over the last few tanks from 24.5mpg to 20.2 mpg averages. I noticed a rich exhaust smell when I'm idling and figured it was time to clean the mass airflow sensor again. It's been about 15,000 miles since I last cleaned my mass airflow sensor so I went ahead and pulled it and cleaned it. It may be getting to be time for a new one. Just topped off the tank after cleaning so we will see how that affects mileage.

Have been watching videos on how to rebuild a Volvo 5 cyl head lately. My plan is to grab a head from a junkyard, overhaul it, clean it up, maybe a small portion and polish while I'm at it. Once that's finished I'll swap the head, replace the timing belt and water pump, new exhaust manifold, drop the oil pan and replace the oil gaskets. That'll be a fun two day project!

[June]

Okay, just realized it's been a month since I updated last. No major repairs. It's been over 80 degrees F here for at least a month now. My mileage slowly creeped down over the last few tanks from 24.5mpg to 20.2 mpg averages. I noticed a rich exhaust smell when I'm idling and figured it was time to clean the mass airflow sensor again. It's been about 15,000 miles since I last cleaned my mass airflow sensor so I went ahead and pulled it and cleaned it. It may be getting to be time for a new one. Just topped off the tank after cleaning so we will see how that affects mileage.

Have been watching videos on how to rebuild a Volvo 5 cyl head lately. My plan is to grab a head from a junkyard, overhaul it, clean it up, maybe a small portion and polish while I'm at it. Once that's finished I'll swap the head, replace the timing belt and water pump, new exhaust manifold, drop the oil pan and replace the oil gaskets. That'll be a fun two day project!

I always notice less mph during the summer months. I understand in areas like mine the EPA mandates "summer blend" gasoline. It could be a factor, also I understand cooler air = more power at least with turbo like my car. As I recall Herman is NA so I don't know if it is a factor for NA engines. In the last month my car has lost several miles per gallon.

My car has been in service since 12/ 2003 and has never had the air flow sensor ever touched as well as the oxygen sensors are untouched as well. I do burn Shell premium only and completely service the car by or more often than the maintenance schedule booklet requires. I change all the fluids and filters way more frequently the rest by the book. June

[Rattnalle]

The hotter it is the better economy I get for some reason. Though above 25C the difference is small.

[mrbrian200]

I always notice less mph during the summer months. I understand in areas like mine the EPA mandates "summer blend" gasoline. It could be a factor, also I understand cooler air = more power at least with turbo like my car.

I'm not sure I'm willing to go along with calling the climate you experience in Jacksonville between November to March as 'winter', June.

From my perspective you have three seasons down there... Sprimmer, Steammer, and Falmmer.

Anywho, the summer blend packs a slightly higher bang for the buck. According to ecomodder Aero & rolling resistance calculator, summer petrol contains 114,500 BTU/gal (labeled as fuel density energy) while winter blend has 112,500 BTU/gal. All else equal you should get better econ using summer gas. Just a guess: I'm guessing during the summer you drive around most of the time with the AC cranked.

[June]

I always notice less mph during the summer months. I understand in areas like mine the EPA mandates "summer blend" gasoline. It could be a factor, also I understand cooler air = more power at least with turbo like my car.

I'm not sure I'm willing to go along with calling the climate you experience in Jacksonville between November to March as 'winter', June.

Anywho, the summer blend packs a slightly higher bang for the buck. According to ecomodder Aero & rolling resistance calculator, summer petrol contains 114,500 BTU/gal (labeled as fuel density energy) while winter blend has 112,500 BTU/gal. All else equal you should get better econ using summer gas. Just a guess: I'm guessing during the summer you drive around most of the time with the AC cranked.

I run the climate control in the car year round. I am sure the compressor works harder in the summer heat. Also I live at the beach and the traffic is much worse during the summer now that I think about it. Definitely the car feels less powerful during the summer for some reason? June

[mrbrian200]

I run the climate control in the car year round. I am sure the compressor works harder in the summer heat. Also I live at the beach and the traffic is much worse during the summer now that I think about it. Definitely the car feels less powerful during the summer for some reason? June

Probably a combination of traffic and the climate control/engine cooling fans running more constant at higher speeds.
A previous car, '95 Cirrus, had issues with frying TCM/ECUs because they were unprotected in the engine compartment too close to the front exhaust manifold , not in a nice fan cooled box that draws air from the passenger compartment like the Volvo .

The only solution I found that kept that Chrysler from frying out/having to replace those computer modules on a yearly basis was to rig the radiator fan to run low speed all the time when the ignition was on.
There was notable decrease in econ due the parasitic fan electrical load (somewhere around 10 amps). Highway econ dropped from ~37mpg to 34.

Electrical loads make a difference, and large DC fans draw significant amounts of electrical current.

[June]

I run the climate control in the car year round. I am sure the compressor works harder in the summer heat. Also I live at the beach and the traffic is much worse during the summer now that I think about it. Definitely the car feels less powerful during the summer for some reason? June

Probably a combination of traffic and the climate control/engine cooling fans running more constant at higher speeds.
A previous car, '95 Cirrus, had issues with frying TCM/ECUs because they were unprotected in the engine compartment too close to the front exhaust manifold , not in a nice fan cooled box that draws air from the passenger compartment like the Volvo .

The only solution I found that kept that Chrysler from frying out/having to replace those computer modules on a yearly basis was to rig the radiator fan to run low speed all the time when the ignition was on.
There was notable decrease in econ due the parasitic fan electrical load (somewhere around 10 amps). Highway econ dropped from ~37mpg to 34.

Electrical loads make a difference, and large DC fans draw significant amounts of electrical current.

You are right about the fan running on the high speed now. I have noticed it lately. It never is running on high in the cooler months. I only notice the fan because I wait for it to shut down before switching off the engine. Usually a min or two max with ac off.

Do you know if the fan runs at highway speed? Could that also effect summer mpg at like 70? June

[abscate]

Not really June.

It takes about 20HP to cruise at 65 mph, and and a 10 amp , 12 volt load is about 120 Watts or 1/6 HP

You might see a 1% dip at most, hard to measure

Homework...you can measure your required HP at 65 yourself without anything more than a stop watch.

Hint...you need to vary the speed of the car.