saturn mileage

[lovemysan]

Well it seems I've hit a wall or maybe my perceptions have changed. I've got some 50mpg gallon tanks under my belt and it really wasn't that hard. But I've been getting lack luster mileage the past few months and have been increasingly disappointed. So wedsday I decided I'd go for broke and see what the car was capable of. My typical church trip is 80 miles round trip. This is how it broke down

trip out
42miles
55.7 mpg 55mph

trip back (slightly altered route)
first leg
9miles
64.6mpg 40mph

second leg
40 miles
58.5mpg 50mph

So at this point I'm disappointed because I feel there is no silver bullet. The only way to get good mileage is to slow down. My goal for the car is 50mpg at 70mph. Lets face the facts I live 8.5 hours from my home town. I don't want to drive 58mph all the way home. With baby stops thrown in it equates to a 12 hour ride in a small car with baby and another baby on the way(and some of you guys know what that means).

Don't get me wrong I think the car gets fine mileage for what it is but I had hoped that I could intelligently modify the car for more mileage. I'm also realizing that I'm very ignorant on the subject of aerodynamics. I'm further hampered by my lack of education and general mathematical skills.

At this point it still seems to me that the largest gains for me could be made in aerodynamics. I've been reading aero articles and I'm starting to understand some mistakes I made with my belly pan. Look at my mods and tell me where I can improve. Pics in below link

http://s75.photobucket.com/albums/i3...emysan/saturn/

[skewbe]

I always loved the name of your car, I was thinking of it all the while trying to climb a few hills on vacation with the trailer

Anyway, COZX2 just posted some pics, http://www.gassavers.org/showthread.php?t=4200

Just armchairing it here (I don't get anywhere near 70mph in my commute): I think your wheels are chewing on a lot of air (might want to fill them in), and you could lower the car and/or add a front air dam.

[usedgeo]

I think I am where you want to be and your belly pan looks better than mine. Mine is not full length. I have the front half of the car and the rear third. I did not go over the muffler. I have rings around the front wheels and the mirrors moved inside. I have not documented the effect of all the changes. I think mirrors add a spot of drag.

I run 60 psi in my tires and real 180 degree IAT, no resistor for now. I think that is the main difference between mine and yours. My grill block is just blocks of foam stuffed into the grill. Yours looks a lot better than mine.

I am pretty sure mine would get your goal of 50 @ 70 but I have not driven that fast for several months now . Actually my current goal is 60@60 and I think I am getting very close to that. I want to drive a bit faster too.

[lovemysan]

Originally Posted by usedgeo

I think I am where you want to be and your belly pan looks better than mine. Mine is not full length. I have the front half of the car and the rear third. I did not go over the muffler. I have rings around the front wheels and the mirrors moved inside. I have not documented the effect of all the changes. I think mirrors add a spot of drag.

I run 60 psi in my tires and real 180 degree IAT, no resistor for now. I think that is the main difference between mine and yours. My grill block is just blocks of foam stuffed into the grill. Yours looks a lot better than mine.

I am pretty sure mine would get your goal of 50 @ 70 but I have not driven that fast for several months now . Actually my current goal is 60@60 and I think I am getting very close to that. I want to drive a bit faster too.

I think the belly pan in its current state doesn't help enough, simply because its not sealed correctly. After reading the autospeed aero articles and studying the mercedes pans I've discovered that the vents I installed, slow the air under the car significantly. I think it really need skirting inside the the wheels underneath to keep the air at higher velocity. This would also reduce the lifting affect caused by the poorly radiused rear glass and short trunk. I'm considering a trunk extension and vortex generators on the roof. But not before I figure some way to instrument it and test its affect.

[Bill in Houston]

Originally Posted by lovemysan

I think the belly pan in its current state doesn't help enough, simply because its not sealed correctly. <snip>I've discovered that the vents I installed, slow the air under the car significantly. <snip>

Hey all the pictures in your old belly pan thrash thread are blown out. Can you show some pictures of what you are talking about?

[usedgeo]

I forgot to mention that I am not running an alternator. That is not a functional idea for a 10 hour trip.

However, preliminary results suggest that Somender Sing grooves might be good for a 10% gain on a SOHC Saturn. I ran 63.5 mpg today at 60 mph for a bidirection test and around 55 mpg for a short bidirectional test at 70-75 mph.

You might put some valley metal over the exhaust system. I think that would help. I don't think the exhaust heat is going to be a problem.

[cfg83]

usedgeo -

Originally Posted by usedgeo

I think I am where you want to be and your belly pan looks better than mine. Mine is not full length. I have the front half of the car and the rear third. I did not go over the muffler. I have rings around the front wheels and the mirrors moved inside. I have not documented the effect of all the changes. I think mirrors add a spot of drag.

I run 60 psi in my tires and real 180 degree IAT, no resistor for now. I think that is the main difference between mine and yours. My grill block is just blocks of foam stuffed into the grill. Yours looks a lot better than mine.

I rarely see my real IAT much over 140 degrees F. Do you have a picture/description of how you did it? I looked around on the GasSaver forums, but couldn't find a specific post from you that pictures/describes it.

I am pretty sure mine would get your goal of 50 @ 70 but I have not driven that fast for several months now . Actually my current goal is 60@60 and I think I am getting very close to that. I want to drive a bit faster too.

Are you still using your block heater? That would take the edge off the startup from home.

It would be cool if you did a thread on your car like "Peakster's Geo Thread".
(http://www.gassavers.org/showthread....t=peakster%27s)

CarloSW2

[Zvolen]

I need to pay attention to this thread as I only get 30MPG if I am lucky, however it is ALL city driving and I have a AT. Any advice would be helpful, or a list of mods that you have done to help the most. My immediate goal is 30MPG without slowing down to a snails pace.

[usedgeo]

I am still using the block heater most of the time. I did not this morning and I started out quite well but got into slow traffic for a couple miles. I need space to pulse and glide effectively. I don't see how MetroMPG can go so slow.

My intake temp is a function of the belly pan, grill block and something I forgot to mention. I used weather stripping the full width of the hood to keep air from going in under the hood lip. The intake hose is tied up so it pulls air behind the exhaust manifold. My intake temp runs about 20 degrees below water temp. Most of the intake heat is coming from the water.

I aint sure my car is worth a thread yet. Some of these college kids have too much time on their hands . I will think about it. Maybe I should start a web page.

The lovemysan links show better pictures than mine for heated intake air.

Originally Posted by cfg83

usedgeo -



I rarely see my real IAT much over 140 degrees F. Do you have a picture/description of how you did it? I looked around on the GasSaver forums, but couldn't find a specific post from you that pictures/describes it.



Are you still using your block heater? That would take the edge off the startup from home.

It would be cool if you did a thread on your car like "Peakster's Geo Thread".
(http://www.gassavers.org/showthread....akster&#37;27s)

CarloSW2

[CO ZX2]

Originally Posted by Bill in Houston

Hey all the pictures in your old belly pan thrash thread are blown out. Can you show some pictures of what you are talking about?

Pics here:
http://s75.photobucket.com/albums/i3...urn/?start=all