My vehicle is perhaps bit unknown to US market as Citroen did pull out from US market before this car was introduced if my information is correct.
Here it is considered being small family car in US it would be probably something smaller than compact class?
Specs as follows:
Citroen ZX Dturbo Break 1997, motor code XUD9TE
1.9 litre turbo diesel motor, producing 90 HP and ~250Nm of torque that is 184.37lb/ft at 2250rpm.
length 4m (13.12 feet) width 1.7m (5.8 feet) height 1.4m (4.6 feet) 0.13m (0.43 feet) of ground clearance and we have legal limit of 0.075 (0.246 feet), tire flat and suspension compressed fully.
Car without modifications is now getting around 53MPG(US)
My driving is on highway, however our roads are not as nice as in some other countries, so we have lots of hills and curves, roads are narrow and often speed is limited to 50MPH, also my car has 50MPH limit on it's back.
I usually don't drive less than 100 miles when I start the car, so warming up does not affect so much to me.
Steep long hills do cause need of bit more cooling than flat areas, but it is rare that we get temps over +25C.
Took roof railings off and filled hood gaps, also gaps around front lights and taped lower portition of upper grille, upper portition brings cool air to intercooler that sits at top of motor.
Next weekend I should know if those had any effect, however conditions have been very windy so even to get same MPG as before is going to be less fuel consumption.
Photo is from
Allcars.com
Here is how car looks as standard:
I did poor job of photoshopping what I would like to do:
From front:
Airdam, to limit airflow underside of car and to block part of lower grille, Plan is to run it straight down from foremost edge of bumper and to follow bumper curvature to sides, also lower edge of airdam should be bit lower than current front bumper is.
Issues with here can be that I'm increasing frontal area too much to have any benefits? Underside of car is rather ugly.
Front wheel well cover, just small one to make gap bit smaller, don't know if it would have any meaningless value, but I will be testing it with duct tape and cardboard.
Hood spoiler thing at back of hood, from red circled areas I hear lot of wind noise, I hope to guide air over those places, but I'm unsure if drawn location is good (it is bit similar in aerocivic), or maybe at front edge of hood it would be better?
Rear wheel well cover, top of wheel well is already made straight by factory, but I have seen many putting good covers there and probably for reason, should be rather easy to do and test.
Lastly, but not leastly, is extension of roofline, bolted to trunk lid, shape is what I thought would give some separation help and should perhaps function, but I'm the newbie here, don't know about much, I have read about 15 degrees, but I think it should also be bit curved as in original Kammback vehicle of 30's?
What is not seen is bottom of car, from front axle to front and from front of rearaxle to rear bumper area is a real mess, those I hope to cover with some material, I don't think that we have coroplast over here, so have to be creative about it. From rear I think little less angle and bringing bottom out a bit, so it is past bumper line, might work out well enough?
I have mudflaps and I'm hoping to make some miniboattails for front wheels so that I would not get so much penalty from mudflaps, car gets really easily very muddy from it's sides so I hope to get improvements to this area too.
Car has cd of 0.36 as standard, don't know how much roof railings add, but at least there is bit less noise, however wind still grabs car very hard.
This vehicle has no value as of money, it is very beaten up by unknown persons at the parking lot and during winter huge chunk of ice that flew towards me from big rig, took part of front bumper with it, so it is very ugly and nobody wants it, so it is pretty much same what I do with it now, however it is my main transportation and I need to haul lot stuff in it so trunk need to be usable as it is now. Good point is that there is full year of MOT (we have yearly inspection of vehicles here), probably will not pass next MOT without major work so this is rather free experiment.
Primary goal is to get off from boost at 50MPH, it is now 0.05-0.1bar on boost at that speed and getting any of boost will increase fuel consumption radically as that is nature of old tech diesels. Second goal is to get under 4l/100km consumption, that is to get into 59MPG(US), I don't know if these modifications will get it any better than that as shape, motor and gearing is what they are. Bigger tires did not go so well, added consumption by over 20%, car had not power to go up hills.
I'm interested in hearing your opinions as it is perfectly possible that I'm thinking something completely wrong here, I'm just 'going with the flow' meaning air flow and what others have done.
Beauty is in functioning form, ugly are chrome fashion and bling.