Method to madness (Fuel Economy Testing)?

[Southcross]

So, I've begun planning my modifications... What's got me stumped is how in the world, around the "Mile High City", I'm going to perform my testing. Between Wind/Weather/Temp, Traffic, hills & FRAKING MOUNTAINS... I know I need "apples" to "apples" tests, so Idealy I don't want to break my tests up over inconsitant periods of time.

so.... I'm Wondering...

Should I plot a simple "Repeatable" path? (instinct tells me yes)
How long should should the drive be? Approximate 1 Gal usage (i.e. Approx 30 miles), 2 Gal (60 miles)?
I'd think that for the best apples-apples comparison, I should attempt to fill up at the same station?

I know in the "scientific" world they have pre-metered fuel, measure distance and how long it takes to go through said amount of fuel... (or how much is remaining and figure out usage divided by distance)... I don't have that kind of luxury

[TestDrive]

Carbureted (so mpguino won't work)?

If so, where is the fuel pump located?

If you don't want to burn lots of gasoline just testing, I'm thinking a manually switched aux fuel tank - like a full sized pickup or suv with dual tanks - only a super tiny 2nd tank (1-2 quarts). Even at only $2/gal it won't take many test runs to pay for itself.

[Big Dave]

I do my testing using my fairly long (50 miles one-way) balanced (one-third urban, one-third rural roads, one-third Interstate) circuit for real-world MPG testing.

Since I don't have precision fuel metering equipment, I use long tests and all the inaccuracies average out.

As A result I think a valid MPG testinvolves about 1500 miles. Four fill-ups.

ScanGuage is OK for short-term comparative tests, but snapshots are NOT real world MPG

[Southcross]

Originally Posted by TestDrive

Carbureted (so mpguino won't work)?

Mechanical CIS fuel injection... the fuel pump runs a super high PSI (75psi minimum), a minimum flowrate of 85L/hour, plus if it runs out of gas flowing through they tend to burn up ($185 new).... not to mention a significant air-bubble in the CIS system can lead to all kinds of issues.
There is no actual "ECU", only an Emissions Control Unit to fine-tune adjust the mixture.... saddly to Stoich (I've got my work cut out for me to hit my goals of 35/40 MPG)... so Scan Gauges and the like are no-bueno

[Southcross]

Originally Posted by Big Dave

I do my testing using my fairly long (50 miles one-way) balanced (one-third urban, one-third rural roads, one-third Interstate) circuit for real-world MPG testing.

hmmm... good point on the "mix", I think I can pull off a good 50/50 of Highway/City

[hummingbird]

Southcross, Just to get the context... What makes you persist with this old ghost of a vehicle?

[Southcross]

Originally Posted by hummingbird

Southcross, Just to get the context... What makes you persist with this old ghost of a vehicle?

becha I spend less on maintenance in a year than what you pay for insurance and bank note in a month

[Bicycle Bob]

Bravo. I averaged under $200 per year for parts and depreciation on old Toyotas for a decade. I think my cars are appreciating now, but it is taking more work. Considering what generating money does to the planet, no expense is unimportant - the fuel bill is just the hardest one to work on. Replacing a car makes a lot of factory smoke.

[Southcross]

Originally Posted by Bicycle Bob

Bravo. I averaged under $200 per year for parts and depreciation on old Toyotas for a decade. I think my cars are appreciating now, but it is taking more work. Considering what generating money does to the planet, no expense is unimportant - the fuel bill is just the hardest one to work on. Replacing a car makes a lot of factory smoke.

don't get me wrong.... if your going to buy a new car, get the most efficient one for your buck... but if your going to replace a carjust for the economy, it reminds me of the saying "The Prius is an Economy car for people who can't do math". A $300/month car payment + Insurance for 30% better gas mileage that what I'm getting right now.... I would have to drive 6,500 MORE miles per month to "save" money