Meet Mr. Corolla

[spdfrk]

The reason you can't coast well is that you either have caliper pins that need lubrication and the brakes are dragging or you need to put some fresh synthetic fluids in the engine and transmission. Worked like a dream in the wife's Acura auto.

[LeanBurn]

-Get a Scanguage, the details it tells you will allow you to see the results of your driving methods far better than reading about them. Driving style is 90% of the battle. Once optimized other mods contribute...

-I run Prius wheels on my Corolla. They are very light and they chose them for a reason. If you can't find Prius wheels that will fit, see if there are light alternatives as previously mentioned. Aero modifications make more difference at highway speeds. At city driving speeds momentum of course is your ally and aero mods will play a smaller role. No to the spoiler over rear window. You want to keep the air flow attached. Do an upper grill block, leave the bottom open. Look at putting a bumper chin to radiator pan with coroplast (super cheap and effective).

-Can your car shed any weight? Getting stuff all out trunk except for essentials...then more aggressive measures, seats etc.

-Run as skinny tires as advisable. Stock size is 175/60R14 skinnier would be 165/65R14 or even 155/70R14 would work and still keep fairly accurate speedo. Keep them aired up to 40psi or more to provide the lowest rolling resistance.

-Get fresh transmission fluid.

-Plug in block heater on 3hr timer for your morning commute to have everything warmed up and ready to provide optimum fuel combustion faster.

[aerohead]

I GOOGLED an image of your car.It looks like Toyota has already covered the airdam issue.
The nose of the car is virtually 'ideal' according to Hucho's metric.
There might be a little to be gained with some grille-blocking.
If only 20% of your driving is at 'speed',I'm not sure what aero mod returns on investment are going to be.
The US loses $75,000,000,000 a year on aero drag,but that's for actual highway driving.

[tcaud]

Originally Posted by aerohead

I GOOGLED an image of your car.It looks like Toyota has already covered the airdam issue.

You mean a 2002 Corolla? No they don't have air dams. You may be looking at a more recent model. On 2002 Corolla the underparts hang at least an inch below the bumper.

The nose of the car is virtually 'ideal' according to Hucho's metric.
There might be a little to be gained with some grille-blocking.
If only 20% of your driving is at 'speed',I'm not sure what aero mod returns on investment are going to be.
The US loses $75,000,000,000 a year on aero drag,but that's for actual highway driving.

Is above for all vehicles or just cars/light trucks?

[aerohead]

Originally Posted by tcaud

You mean a 2002 Corolla? No they don't have air dams. You may be looking at a more recent model. On 2002 Corolla the underparts hang at least an inch below the bumper.



Is above for all vehicles or just cars/light trucks?

The airdam on the Corolla is integral with the front fascia.It even has a vestigial splitter.
It's true that it isn't as 'deep' as the actual low point of the underbody,but it would be just a matter of giving the belly some gentle upsweep,as Tesla (current low drag champion) does,to terminate at the bottom of the airdam.Look under an S model next time you're around one.

Hucho's 'ideal' nose dates to 1976.
It's predecessor can be found with R.G.S.White's search at MIRA in 1969.
White's predecessor can be found with Fachsenfeld/Kamm in 1935,which is linked to Jaray in 1922,which is linked to Eiffel,1889.This is very old technology!
It can be used in all light and heavy vehicles below 250-mph.The atmosphere doesn't discriminate.
The dollar figure is just for the highway portion of 261,000,000 autos and light trucks,circa 2015,@ $2.249/gallon,13,476 miles/year/vehicle,and 21.4 mpg Combined; using 45% of total miles as EPA HWY.

[tcaud]

@Aerohead, you seem to be suggesting that it's not worth trying to aeromod a car that usually is driven below 65mph. Which if that's the case then it's the case and no use worrying or wasting effort anymore.

Can we make the following observation, that high speed economy improvements are to be made thru aeromods, and low speed improvements through engine mods/behavioral alterations?

[Daschicken]

Originally Posted by LeanBurn

-I run Prius wheels on my Corolla. They are very light and they chose them for a reason. If you can't find Prius wheels that will fit, see if there are light alternatives as previously mentioned. Aero modifications make more difference at highway speeds. At city driving speeds momentum of course is your ally and aero mods will play a smaller role. No to the spoiler over rear window. You want to keep the air flow attached. Do an upper grill block, leave the bottom open. Look at putting a bumper chin to radiator pan with coroplast (super cheap and effective).

Have you seen the rear window angle on a 2002 corolla? If the airflow can't stay attached over the rear window of my accord, then it definitely won't stay attached over the corolla's rear window. However, IF you make a window spoiler, make it significant, like 8+ inches long. A kammback would be even better. Absolutely agree on the bumper to radiator panel. That is a bad aero/cooling spot on WAY TOO MANY cars.

Here is video evidence of my accord's rear window flow separation. Not a great video, but its what I got.

https://www.youtube.com/watch?v=TSvW7Nh6-2k

[aerohead]

Originally Posted by tcaud

@Aerohead, you seem to be suggesting that it's not worth trying to aeromod a car that usually is driven below 65mph. Which if that's the case then it's the case and no use worrying or wasting effort anymore.

Can we make the following observation, that high speed economy improvements are to be made thru aeromods, and low speed improvements through engine mods/behavioral alterations?

As of the mid-1980s,80% of available power was consumed by aerodynamic drag according to Hucho,with the remaining 20% to rolling resistance.
So it's pretty obvious that if you're looking for highway savings,then you're gonna attack air drag.
If only 20% of your driving is on the highway,then you're going to realize less benefit from aero mods.
In urban settings,traffic jams,slowing,acceleration,stops,etc. are going to eat into your fuel budget.This is where EVs and hybrids shines,as they can recover a large % of what would otherwise be entropy,as velocity is converted to brake heat.Plus,an electric motor has an equivalent BSFC which is a third of an ICE vehicle.
Reducing mass is the most important factor in stop and go.
It's expensive.
Avoiding traffic,if possible would be great.
Synchronized traffic lights would be great too.(we lose $62 for every $1 not spent on signal light synchronization).
Hyper-miling,as long as you don't affect the mpg of any other motorists around you.

[freebeard]

Can we make the following observation, that high speed economy improvements are to be made thru aeromods, and low speed improvements through engine mods/behavioral alterations?

Certainly. There's always an edge case to anything. In this example the gray area in the middle. Changing the axle ratio or tire height can affect top speed, which is limited by the increasing power requirement for [higher] cruising speed.

Reducing mass is the most important factor in stop and go.
It's expensive.

Pound for pound, remove reciprocating or rotating mass first. I have this theory that titanium valve spring retainer clips may help as much as alloy wheels.

[/QUOTE]Avoiding traffic,if possible would be great.
Synchronized traffic lights would be great too.[/QUOTE]

The future is already here. It's just unevenly distributed.

[tcaud]

I figure I can block the top grill with a piece of cardboard, but what good will this do me mpg wise, and how?