Your best modification
 

Hi guys, can you advise the best modification that you made to your car. When I say best it gave you a very "Significant" increase in MPG. and you have modified yourself as a driver already=)

Thanks guys.

I was going to say "slowing down" but i figured you wanted hardware so i'd say getting the tires up to sidewall, followed by a grille block, followed by a belly pan, lighter oil.

ollie

50 psi... and it's *free*!

Shed excess weight... that's *free* too! ;)

gasti_ako -

After changing how I drive (ScanGauge was part of that), my 5th gear swap :

http://ecomodder.com/forum/showthrea...swap-2779.html

CarloSW2

the question arose when i tried to view each fuel logs and there seem to be different modifcations that affected MPG significantly. also, i created this thread because it would be a long shot to check each log.

for those that replied thank you. =)

anymore?

It depends
 

The "best" modification past pumping tires and driving style will vary with the vehicle. Large grilles should be blocked. Pick-ups need a bed cover. Bellypan is the answer for a vehicle with a lot of turbulence underneath. They will all add something to being more aero. Timing and WAI may be engine mods that will be the best for you. Find someone with a similar vehicle and see what they have done. It may also keep you from trying something that didn't work.

my pasenger wing mirror and aerial delete was very impressivly successful. way more than the 2% that i was hoping for. i measured 17% initially but i think its more consistently like 8%, at least 5mpg (imperial). i have a small efficient petrol car that is otherwise well areo'ed.

Hmm, lots of things have worked on different cars.

Best one by in my experience was swapping out an auto trans for a manual one. Cost about $500 (parts car w/stick + misc) and a very long weekend, but took it from 25mpg to a 50mpg in-town hypermiler, with appropriate techniques.

Of course you can get similar results with an auto, I think Gerdes does, I just felt more confident with a bump start backup for my starter, especially when the starter starts turning over slow. And the accelerating won't have the converter slip with a clutch.

Tires is definitely #1. After that the grill block, then mirror delete/swap. But like others have said, it depends on the vehicle and where you're driving. Areo mods don't mean as much when 80% of your driving is city, and weight reduction doesn't mean much when 80% of your driving is highway.

90% of my driving is highway so it's all aero for me. Next up is airdam and partial front undertray testing.

I'd love a manual tranny though...

Boat tail. In addition to significantly increasing mpg's, it also doubled the luggage space available behind my back seat.

Check the basics first. Tune up your car.
 

My favourite mod was removing my alternator and running on one or two deep cycle batteries depending on the distance/load. went from 20 to 26mpg.

Second best was a mod group: grille block / deflector / 2 inch airdam. went from 29 - 38 mpg

Third Tire pressure.

Timing if retarded can cost mpg. You can usually advance past stock 5 degrees especially if you don't pull trailers or have lead loafers. If your engine is knocking retard a couple degrees at a a time till it stops.

If your car has high mileage check your oxygen sensor. Mine was toast and was actually working in reverse causing both an over high and low fuel mix.

And, I might mention, on MANY cars this is a V easy mod - the factory mirrors fold in toward the body (I guess to avoid damage in car washes and so forth) allowing you to do an A/B comparison of mileage impact!

This is kinda slick, no? :D

USDM CiViC

YouTube - JDM Power folding mirrors

Prius

YouTube - My Prius Auto Folding Mirrors 1

Personally, I've thought about removing my outside mirrors - I know they kill mileage at freeway speeds, but mirrors come in handy in bumper-to-bumper city traffic.

Heh!

I'm gonna have to look into these 'JDM power folding mirrors'.

Dude, the japs always keep the best for themselves, don't they!?!?!

most significant modification to any car....

change in driver

most significant change can be a driver..but more not about driving, but opening the mind to flaws over marketing lies and deceipt.Has the geas mileage on a new cars window EVER been correct? :confused:

The gear change in the saturn for example. Excellent.
bigger gear ratios for boxers is a LEGEND in same comparision....all on same fuel, hence instant hypermiler..Glad to see that option for the bigger inlines.

I like what I learned here. The big change really is the drivers mind set. Step one no doubt...Doubt it all, you may get someplace if patient...

ScanGauge

I can't afford a new driver.

A custom computer tune to increase mileage, after cutting open the factory airbox and replacing the filter...

probably my spark plugs. that would be the biggest. after that raising my tire pressure (lots of highway driving, helped alot) and also getting a fresh air filter when i bought car.

and the all important driver mod :)

Grill block by far!

Engine Block Heater

thanks for all your replies. I am now planning with the tires and wheels: 14" or 15", 45 PSI that are low resistant rolling. Next would be a grill block off.

would carbon fiber parts offer significant decrease?

how do you know if the driver is a good hypermiller? I have a friend who says he is a fuel efficient driver but I think its bull. I notice the way he drives and i think I am still better. He says that he is getting good fuel mileage out of its car but he can't even show me a fuel log. Basically he assumes his MPG.

And if ever he is correct about the MPG, i think its not the driver but the CAR!

Scangauge for me

Tires, so far. I am still really working on the nut behind the wheel. It's hard breaking years of habits...

Most significant changes (beyond adjusting the nut behind the wheel):

Replaced 3.73:1 gears with 3.08:1 gears +3 MPG

Fastback bed cover +3 MPG (over open bed)

Mine worked out to saving about a nickel a day (gas savings vs 2 hours with 400 watts) on a nearly $400 investment.

Your heater cost $400?

Frank, the heater costs about $40 with all of its excess markup. It's the labor for the install at the stealer, a frame cross member has to be removed. I wish it was done at the factory. It would cost 2 to 10 bucks there total. Add the timer and a winter type extension cord and it's not a cheap investment.

Regardless of the cost, it helps on the first trip of the day and it saved about 5 cents a day during the non-summer months.

best
 

Boattails

Besides fixing the driver, I'd say

50% Underdrive pulley
Luggage rack removed
+5 psi

Air dam and some seam sealing on it's way.

Finding a good independent garage is a good idea to save money too! Also if you get them to quote the job beforehand they can't make you pay more even if "complications" occur with out your permission.

Back to the topic at hand, best mod was the scanguage, which adjusted the driver. Then air pressure and that's all I've done really. Both cars have block heaters already so when it gets closer to winter I'll set up the timer and cords.
Ian