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.