3 mpg gain with $80 worth of sheet metal
Well I just got back from a MPG run with my 97 Volvo 960. It was my usual base line route I always take after making any kind of mpg mods to the car. Speed is held to 65 mph and tires are inflated to 40 psi. I would like to thank Justin (tjts) for the incentive to make the belly pan mods. I wish I had some pic's for you at this time but hopefully I will be able to get some of the under carriage by the end of the week for you guys. My base mileage on this run is an even 28.0 mpg which was run in July. Well to the meat of the facts. At the front I enclosed the openings between the bottom of the fenders to the edges of plastic splash pan with Aluminum. This is an open area under the battery and the corresponding passenger side. Heading towards the rear I encased the independent suspension in a aluminum box with a steel air deflector plate attached to the bottom of the suspension cross member. This was done to keep the air from being pulled up into the IRS frame work while it is flowing under the car. From there I ran an aluminum plate all the way back to bottom of the rear bumper. I did leave the rear muffler exposed due to the heat and a heat shield was implemented by the catalytic converter to control some of the heat. All in all I got an astounding 3.0 mpg increase with this mod. This has been probably the best mpg increase from all the mods I have made. When I bought the car Feb 05 I got 25.3 mpg on the highway and today 31.0 mpg. 5.7 mpg or 18.4% increase is nothing to complain about. Plus I figure next spring I'll spend a little time cleaning up the rest of the under carriage. That should be worth another 1/2 to 1 mpg. For those that are interested in all the mods. This RWD car weighs in at around 3500 lbs and has a Cd of .36 I started with an Auto-Rx engine cleaning. A clean engine is an efficient engine. That helped me get the car to 26.3 mpg, Then I swapped out all the fluids for synthetic and I saw 27.4 mpg. I then increased the tire pressure from 36 psi (factory) to 40 psi and saw 28 mpg. With the addition of the belly pan mods I now get 31 mpg. My Scan Gauge matched the gas pump when I filled up with 8.238 gallons of gas for 255.7 miles.
Comments
3 mpg gain with $80 worth of sheet metal
Awesome, very nice! I want pics now man. Is your Volvo in the MPGResearch Garage?
3 mpg gain with $80 worth of sheet metal
Al
Well done! That is a great increase. Would be great if you could somehow gets some pics. Please keep us updated on this and any other mods/tests you do.
3 mpg gain with $80 worth of sheet metal
Ok guys here are some photos of the mods I did including the car it self. [url]http://photos.yahoo.com/ajspgh@sbcglobal.net[/url]
3 mpg gain with $80 worth of sheet metal
THANKS so much.
Very nicely executed installation.
3 mpg gain with $80 worth of sheet metal
Very very nice job man, wow. Gives me ideas!
3 mpg gain with $80 worth of sheet metal
Al Could you update this thread from time to time with you highway fuel economy over the long term? I am going to start a aero project on my 960 this weekend. I don't think I can archive the same results as you have because my 960 has the earlier style front font end which is not as aerodynamic. Also looking under my solid axle wagon the 25mm sway bar hangs very low relative to the rest of the body. Either way I'm going to start on a new front end belly pan that will also replace the plastic engine tray. Mine is falling apart. Its going to be hinged to facilitate oil changes.
3 mpg gain with $80 worth of sheet metal
That's some neat work. Can you say what the major areas covered were?
* pan under engine from front?
* gas tank?
3 mpg gain with $80 worth of sheet metal
The front coverings were to close up the open area's between the fenders and plastic splash pan under the engine. The rear area was to cover up the area under the trunk where the spare tire sits. and the open area to the bumper. The spare tire area looked like a donut. It was a big round tire sized protrusion from the rest of the area with an indentation in the middle that you could have put 1/2 a basket ball in. That is the reason for the big metal plate to the bumper. The bumper assembly that is pretty low and was probably grabbing a part of the air flow and acting like an air brake. The plate also lets the air bi-pass this area. The area in front of the IRS I put in a deflector to keep the air from interacting with the frame work of the suspension. The suspension sits in an U shaped depression in the floor of the chassis. When I saw that I knew I had get the air around that depression as well as the IRS frame work. That is the main reason for the deflection plate under the main suspension I beam. You want to smooth out the air as much as possible while it is running under the car. I would say in most cases if you can get the air smoothly past the rear bumper, that is probably the biggest and cheapest gain you will find under most cars and trucks. You have to put the car or truck up on a rack and take a close look at everything from the front bumper to the rear bumper. Any Holes or pockets need to be filled or covered. Anything that is hanging in the airflow needs to be covered or the air needs to deflected around or over it. If you don't think that little piece of metal hanging down matters then get the car to 50 mph on the highway and stick your arm out the window into the air flow. Knife edge your hand then turn it vertical. Big difference!!! And how big is your hand compared to the things hanging under the vehicle?
3 mpg gain with $80 worth of sheet metal
I spent a considerable amount of time checking out all the pics (dial up) and must say, awesome job. I'm trying to figure out how to enclose things more completely while allowing venting for the exhaust system (on mine, of course).
Mike
3 mpg gain with $80 worth of sheet metal
I'm impressed by your 3 mpg increase. I have a 1998 merc mystique 4 cyl, 5spd. When I bought the car I was getting anywhere from 28 - 34 mpg on gas. Like you I am now carrying 40 psi in tires that are rated at 44 (this because the car mfg only recommends 34) I know I could safely put more in the tires but don't want to adversely affect the car's handling. I changed over to synthetics in the crankcase and transaxle. I installed a cutout switch on the a/c so I can shut it off when the panel or defrost is on. I installed the full moon racing wheel covers to reduce drag. I like to keep the car including windows and license plates waxed with Nu Finish wax (I believe this reduces drag). I installed new spark plugs. I put a scan gauge into the car and with all of this and modifying my driving habits ( I do coast a lot and on the highway I use the cruise control and keep my speed at between 53 - 55 mph. On gas I have achieved 48 mpg with a tailwind and averaged about 42 mpg. Then I switched to E85. I used the FlexTek conversion kit. I now average 32 - 33 mpg on an "inferior" fuel but I am getting more mpg with E85 than the car is rated at on gas (26 - 28 depending whose stats you use). I wonder what your mod would do for me?
3 mpg gain with $80 worth of sheet metal
Definitely awesome work. Will be considering that for my Volare :)
Nice Volvo Upgrade..
Wow. Good to know that. I can't believe that it can improve like that. Impressive! Kind of doing that too on my volvo. It'll be great to add this together with the volvo accessories and good parts. I think any volvo run like this will be awesome.