VW Passat owner increases car's mileage from 18 km/l to 24 km/l via simple aero mods

RahulNagaraj · 25th October 2023, 17:05

According to a media report, YouTuber B Sport, managed to increase his 2006 VW Passat's fuel efficiency by an impressive 33% via a bunch of straightforward aerodynamic modifications.

https://www.youtube.com/watch?v=Cipry8uV5QY

Before the modifications, B Sport recorded a fuel economy figure of 43 mpg (18.2 km/l). However, post the aerodynamic modifications, he registered a fuel efficiency figure of 57 mpg (24.2 km/l) on the highway and 52 mpg (22 km/l) during his regular commute. This is an impressive increase considering the car is powered by an old 1.9-litre diesel engine paired with a 5-speed manual transmission.

VW Passat owner increases car's mileage from 18 km/l to 24 km/l via simple aero mods-vwpassatmods.jpg

Talking about the modifications though, the YouTuber removed the car's roof rack and added 40 mm lowering springs. The car's radiator and brake cooling ducts have been covered from the back side, the bottom of the car has been smoothened considerably and the cooling ducts for the transmission now have aerodynamic covers. But the most prominent change is the inclusion of moon disk wheels, replacing the car's stock multi-spoke alloy rims.

B Sport, though, specifies that the modifications have been made to suit his use case, which mostly includes doing 80 mph (129 km/h) on the Autobahn. This combined with the extremely light load on the vehicle, allows him to sacrifice some of the cooling the car would normally get.

The YouTuber reverted the car to its stock condition, before selling it off - making it a fun project.

Source: TheDrive

Link to Team-BHP news

CLS_06 · 25th October 2023, 22:18

That's an impressive jump in fuel economy
While mods are really well thought .he knows his machine inside out .
I think moon discs can be applied to any vehicle .it will have a good impact

AKSarkar1 · 26th October 2023, 09:49

Fun experiment but nowhere near practical for the real world

Reminds me of the Top Gear episode where they taped their cards with absurd mods while doing drag times on the salt flats in USA

sainyamk95 · 26th October 2023, 11:50

Fascinating experiment due to its apparent simplicity and focus on aerodynamics. While it is awesome how manufacturers and designers make sure the car can withstand just about any and all conditions, it is very interesting how they can be adapted for such specific use cases. However, I do wonder if the rather simple and smooth (?) shape of the Passat estate played a role in improving the mileage to such an extent, and if modern SUV-inspired bulky designs would achieve such an improvement. Has anyone here on TBhp done something similar? 🤔

SmartCat · 26th October 2023, 12:39

Does aerodynamic drag has such a big effect on fuel economy? Is there known correlation? (eg: reduce co-efficient of drag by X% and increase fuel economy by Y%)

I think speeds matter too - within city limits, any such mods will have negligible effect on fuel economy.

Passatman · 26th October 2023, 13:03

These 1.9TDI PD engines make for very efficient workhorses! OP has the 77kw oil burner which is pretty frugal, though a tad underpowered ( my opinion) . My passat has the 96kw 1.9 TDI PD which offers better response to the right foot while also being equally frugal in sipping fuel.
My car still runs stock and even after 180 k kms comfortably returns 60-65 mpg on our highways ; the best i have seen is 99.9mpg !! No moon discs, no taping up the air ducts and just the stock engine and gearbox underbody shield!
VW engineers I guess were pretty good a couple decades ago ! And maybe all retired or pushing daisies now!

narayans80 · 26th October 2023, 13:14

The Volkswagen 1.9 and 2.0 TDI are already fuel efficient no? The weather should also play a part, barring peak winters when you need to use heater. One can reduce their HVAC usage, which significantly contributes to drinking fuel.

That lowering by 40 mm on a car that's already 150 mm unladen GC is hugely impractical, how does he even get around town roads in Germany?

And being Europe, aren't you mandated to change to winter tyres for 6 months a year?

For India, that GC loweing is not going to work, and one can reduce their AC usage in Nov-March months. Apart from this, planning your drives will drive your FE. These are non-invasive hypermiling that don't require "simple mods" done by a former Volkswagen employee and motorsporting engineer.

25th October 2023, 22:18	#2
CLS_06 Newbie Join Date: Aug 2022 Location: Ludhiana Posts: 10 Thanked: 12 Times	Re: VW Passat owner increases car's mileage from 18 km/l to 24 km/l via simple aero mods That's an impressive jump in fuel economy While mods are really well thought .he knows his machine inside out . I think moon discs can be applied to any vehicle .it will have a good impact
	(2) Thanks

26th October 2023, 09:49	#3
AKSarkar1 BHPian Join Date: Jan 2021 Location: Mumbai Posts: 479 Thanked: 1,099 Times	Re: VW Passat owner increases car's mileage from 18 km/l to 24 km/l via simple aero mods Fun experiment but nowhere near practical for the real world Reminds me of the Top Gear episode where they taped their cards with absurd mods while doing drag times on the salt flats in USA
	() Thanks

26th October 2023, 11:50	#4
sainyamk95 BHPian Join Date: Jul 2016 Location: MH43/Belfast Posts: 114 Thanked: 473 Times	Re: VW Passat owner increases car's mileage from 18 km/l to 24 km/l via simple aero mods Fascinating experiment due to its apparent simplicity and focus on aerodynamics. While it is awesome how manufacturers and designers make sure the car can withstand just about any and all conditions, it is very interesting how they can be adapted for such specific use cases. However, I do wonder if the rather simple and smooth (?) shape of the Passat estate played a role in improving the mileage to such an extent, and if modern SUV-inspired bulky designs would achieve such an improvement. Has anyone here on TBhp done something similar? 🤔 Last edited by sainyamk95 : 26th October 2023 at 11:58.
	(1) Thanks

26th October 2023, 12:39	#5
SmartCat Team-BHP Support Join Date: Jun 2007 Location: Bangalore Posts: 6,446 Thanked: 43,152 Times View My Garage	Re: VW Passat owner increases car's mileage from 18 km/l to 24 km/l via simple aero mods Does aerodynamic drag has such a big effect on fuel economy? Is there known correlation? (eg: reduce co-efficient of drag by X% and increase fuel economy by Y%) I think speeds matter too - within city limits, any such mods will have negligible effect on fuel economy.
	(4) Thanks

26th October 2023, 13:03	#6
Passatman BHPian Join Date: Nov 2014 Location: Bangalore Posts: 78 Thanked: 123 Times	Re: VW Passat owner increases car's mileage from 18 km/l to 24 km/l via simple aero mods These 1.9TDI PD engines make for very efficient workhorses! OP has the 77kw oil burner which is pretty frugal, though a tad underpowered ( my opinion) . My passat has the 96kw 1.9 TDI PD which offers better response to the right foot while also being equally frugal in sipping fuel. My car still runs stock and even after 180 k kms comfortably returns 60-65 mpg on our highways ; the best i have seen is 99.9mpg !! No moon discs, no taping up the air ducts and just the stock engine and gearbox underbody shield! VW engineers I guess were pretty good a couple decades ago ! And maybe all retired or pushing daisies now!
	(2) Thanks

26th October 2023, 13:14	#7
narayans80 Senior - BHPian Join Date: Aug 2010 Location: Madras Posts: 3,122 Thanked: 4,534 Times	Re: VW Passat owner increases car's mileage from 18 km/l to 24 km/l via simple aero mods The Volkswagen 1.9 and 2.0 TDI are already fuel efficient no? The weather should also play a part, barring peak winters when you need to use heater. One can reduce their HVAC usage, which significantly contributes to drinking fuel. That lowering by 40 mm on a car that's already 150 mm unladen GC is hugely impractical, how does he even get around town roads in Germany? And being Europe, aren't you mandated to change to winter tyres for 6 months a year? For India, that GC loweing is not going to work, and one can reduce their AC usage in Nov-March months. Apart from this, planning your drives will drive your FE. These are non-invasive hypermiling that don't require "simple mods" done by a former Volkswagen employee and motorsporting engineer.
	(1) Thanks