Now up to 57.3 mpg at 60 mph in my 97 Saturn SC1

[cheapybob]

Originally Posted by The Toecutter

57 mpg is impressive. If you have that already, completing your aeromods would do a bit more than 60 mpg.

As for top speed, assuming you can't reach redline in the highest gear, the increase should be considerable.

The only aero mods left that I can see as feasible for me are a belly pan and rear skirts. I also plan to replace my race tape front end with aluminum modeled after it what the tape has evolved to. I'm trying to get the aluminum to do all the aero mods for under $40, so its a challenge. Even if I keep it down to $40, it will be tough to get a payback in 50,000 mi. unless I can get 1 mpg avg on all driving with it, and that's assuming my free labor and a max of $50 for paint and supplies.

I'm not worried about top speed with this car. With my other mods the car is seriously detuned. Thats the price I'm paying to get high mpg out of a car with a 1.9L motor. I may see if I can come up with a system that switches it to a cold air intake when I press hard on the gas because its pretty sluggish if you're looking for passing power. I was only a 100 hp motor to start with and I've never had it over 4000 rpm. We'll see how it does pulling the sailboat and trailer to Canada in July, LOL.

[The Toecutter]

The underbelly and rear skirts are some of the most significant mods that can be made for the cheapest price. You'll definately see more than a 1 mpg improvement from them, at least a 2 mpg improvement from the rear skirts alone. The underbelly is even more significant.

However, you could also build side skirts, a rear spoiler designed for reduced drag(as opposed to downforce or looks), install shaved door handles, build wheel spoilers, use more aerodynamic mirrors, and seal up all seams(ie. use bondo, sand down and paint as needed. You could have nearly gapless doors and trunk).

It is possible to do those things for cheap, if you're good at scrounging and willing to either work with fiberglass or do some custom fabrication/welding. Even the shaved door handles can be done for cheap on your own, if you're willing to cut into your doors, root around the junkyards for the parts, design a remote-operated system to actually open and close your doors, weld metal plates back to the doors to seal them, and actually sand and paint them back to normal.

Further, you might be using a high tire pressure, but are you using genuine LRR tires? Skinnier tires will also reduce aero drag and if they are LRR tires, significantly reduce rolling drag.

each of those things might not be much by themselves, but added together as a whole, the impact on fuel consumption would be astounding. There are individuals that have heavily modified Honda CRXs to achieve 90 mpg with a cost in the few thousand dollar range for everything. I imagine similar results can be had with a heavily modified Saturn.

[cheapybob]

I might consider doing the wheel spoilers integrated with the belly pan, but other than that I probably won't be doing anymore mods to the body.

As for tires, its a shame that the tires that are on it have so much tread left on them. I looked at replacing them with some that are a larger diameter as well as lighter, and it turns out they also happen to be LRR tires. They are OEM on BMW's I think, and not too expensive, either. Continental ContiPro Contact in 195/65-15

I found an article posted by Matt Timion.....
New Fuel Efficient Tires Could Save Long Islanders $150 And Reduce U.S. Oil Dependancy By 275,000 Barrels a Day


Location: SLC, UT
Posts: 1625
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Original Article: http://schumer.senate.gov/SchumerWebsite/pressroom/press_releases/PR01924.pf.html

SCHUMER: NEW FUEL EFFICIENT TIRES COULD SAVE LONG ISLANDERS $150 AND REDUCE U.S. OIL DEPENDANCY BY 275,000 BARRELS A DAY

Schumer touts new tire technology that cuts reliance
on foreign oil and saves money at the pump

New Schumer study finds less than 12 percent of LI tire stores sell fuel efficient tires – and Schumer reveals where to find them

US Senator Charles E. Schumer today announced a plan to require the federal Government to establish efficiency standards for the replacement tires drivers buy when the originals on their cars wear out. Most current replacement tires are between 20 and 60 percent less efficient than the original tires automakers equip cars with to help meet federal fuel economy standards.

Schumer released data showing that for an extra $5 to $12 per set of replacement tires, the average motorist can reduce his or her gasoline consumption by 1.5 to 4.5 percent, saving $50-$150 over the life of the tires. This data was confirmed by California Energy Commission, which is that state's state's primary energy policy and planning agency.

"If most Long Islanders knew they could invest an extra $12 in a set of tires and then save up to $150 at the gas pump, they'd jump at the opportunity. It's a huge savings for less than the cost of a tank of regular unleaded," Schumer said. "Unfortunately, there aren't enough of these tires, and the ones that are on the market are tough to find. But if fuel efficient tires are good enough when you buy a new car, they should be good enough when its time to replace those tires down the road – and tire manufacturers should make that option available for every car, truck, SUV, and minivan driver."

According to the National Resources Defense Council, the United States could save 275,000 barrels of oil a day by the year 2010 if all replacement tires were as efficient as the originals. In New York alone, efficient replacement tires would save 150 million gallons of gasoline and $240 million a year. Savings nationwide would total between $2.5 and $7.5 billion a year, according to Green Seal Environmental Partners, an independent, non-profit organization that produces Consumer ReportsTM -like investigations into the environmental friendliness of consumer products.

Tire efficiency is measured through rolling resistance, or the amount of energy needed to roll a tire down the road. Because of their higher rolling resistance, replacement tires are as much as 60 percent less efficient than the original tires that automakers use to help meet the federal Corporate Average Fuel Economy (CAFE) standards, according to Green Seal. If all replacement tires were as efficient as the originals, fuel economy nationwide would improve by about 3%, and the United States could save 5 billion barrels of oil between 2007 and 2050, according to the National Resources Defense Council.

Schumer's proposal today directs the National Highway Traffic and Safety Administration, a division of the US Department of Transportation, to establish an efficiency standard and labeling requirements for replacement tires so consumers know if the tires they buy are as efficient as the ones that came as original equipment when their cars were new. These standards would be reviewed and updated every three years to keep up with improvements in tire technology.

Schumer would also create a new consumer information program to promote the purchase of energy-efficient replacement tires including purchase incentives, Internet website listings, and printed fuel economy guide booklets. Schumer said that this information is essential because few drivers know about these tires and even fewer tire retailers in New York and across the nation sell such tires.

Schumer released a new study today of over 100 tire retailers in Nassau and Suffolk counties that found just 12 percent of them currently carry high-efficiency tires. Of 106 Long Island tire retailers contacted on August 4 and 5, only 13 reported carrying any of 16 tire models that are highlighted by Green Seal as fuel efficient. For a list of stores that sell the high efficiency tires click here.

The specific tire models studied by Schumer are the Bridgestone B381, Nokian NRT2, Sumitomo HTR 200, Dunlop Graspic DS-1, Dunlop SP40 A/S, Goodyear VIVA 2, Continental ContiTouring Contact CH95, Michelin Pilot Alpine, Michelin Energy MXV4 Plus, Dunlop SP WinterSport M2, Michelin Arctic AlpineXL, Dunlop Axiom Plus WS, BF Goodrich Long Trail T/A, Michelin XPS Rib, Michelin LTX M/S and Bridgestone Dueler A/T D693 tires. Schumer researchers asked for a variety of tire sizes, from 185/70R14 models appropriate for an economy car like a 2001 Honda Civic to 245/75R16 models that would fit a full-size SUV like 1997 Chevrolet Tahoe.

California Energy Commission research has shown that fuel-efficient tires perform at the same safety level as the replacement tires that are currently used by cars throughout the United States. Tire manufacturers can use materials like silica to stiffen tires and lower their weight. Improved tread design can also improve rolling resistance.

"By guaranteeing that replacement tires are as efficient as a car's original tires, drivers can make a small, smart, and effective investment that delivers large returns – all while decreasing our dependence on oil the oil we import every day," Schumer said.

[cheapybob]

Originally Posted by MetroMPG

that's amazing - nice work. you should really use the gaslog feature. i'm sure folks would like to see your tank-by-tank results too.

my firefly only gets that mileage around 53/54 mph.

Something else I didn't understand...

Why is it that your Metro with its tiny 1.0L motor gets 59 mpg average according to your gas log thing, yet can only get 57 mpg if you drive at 53-54 mph?

What doesn't make sense is that you are getting better mpg in normal driving that what you would get under very advantageous conditions (ie at 53-54 mph drag is very low and you'd be in top gear all the time).

If I was to drive a steady 53-54 mph I'm pretty sure I'd be getting at least 60 and maybe up to 63 mpg. I haven't tried any long loop type test at that speed yet, but that would be my guess for expected results.

[SVOboy]

Something else I didn't understand...

Why is it that your Metro with its tiny 1.0L motor gets 59 mpg average according to your gas log thing, yet can only get 57 mpg if you drive at 53-54 mph?

What doesn't make sense is that you are getting better mpg in normal driving that what you would get under very advantageous conditions (ie at 53-54 mph drag is very low and you'd be in top gear all the time).

If I was to drive a steady 53-54 mph I'm pretty sure I'd be getting at least 60 and maybe up to 63 mpg. I haven't tried any long loop type test at that speed yet, but that would be my guess for expected results.

You're new to the site, which means you haven't become introduced too well to the idea that hypermiling is best done in the mountains or around town. You can't run engine off on the highway,

[cheapybob]

Hmmmm, I don't shut the engine off. If i'm coming up to a light I put it in neutral and roll up to it, trying to time when i get there to when the traffic will be moving again, but that's about it.

I swapped some 1.5 qts of the oil for 5w-20 Mobil 1 and ran the test loop again, but at 55 mph instead of my normal 60 mph. Avg speed was 53 instead of 57. Anyway, the result was 59.2 mpg on the scangage. I was expecting 60, but I may be getting to the law of decreasing returns.

[SVOboy]

Engine off is the way to go. Take a look at the daily mpg thread or some of dan's or darin's (metrompg) threads on driving technique. They're fantastic chaps.

[philmcneal]

i can floor it and still get 50 mpg thanks to engine off technique over a span of 10 miles driving with a dead cold engine with temps at 15 degrees C.

.2 gallons burned or .8 liters.

[MetroMPG]

Originally Posted by cheapybob

Why is it that your Metro with its tiny 1.0L motor gets 59 mpg average according to your gas log thing, yet can only get 57 mpg if you drive at 53-54 mph?

the comments so far are right. city driving just gives you more options for being efficient than hwy driving. there are more cards you can play, and one of the biggest is engine-off coasting. at least around here, the highways don't offer many opportunities to coast.

a few times lately i have been getting higher mileage on round trips of in-town driving than i can get at *any* steady speed in top gear (even 80+ mpg in 5th at 55 km/h).

[rh77]

Originally Posted by MetroMPG

the comments so far are right. city driving just gives you more options for being efficient than hwy driving. there are more cards you can play, and one of the biggest is engine-off coasting. at least around here, the highways don't offer many opportunities to coast.

a few times lately i have been getting higher mileage on round trips of in-town driving than i can get at *any* steady speed in top gear (even 80+ mpg in 5th at 55 km/h).

I have to insert that this may not be true for automatics -- I've found my best mileage cruising at 55, with city driving being the killer. Even with engine-off coasting and/or neutral at the stoplights, it just takes too much energy to get going again (that's with a ease into 20% throttle until desired speed). Any other automatic folks with the same problem? If I did highway driving all day I could get in the high 50's.