[Zatara]

I understand gas mileage is an issue that has been discussed previously, but I'd like to start a new thread dedicated to mods specifically for increasing mileage as opposed to power or sound.

These are related issues of course, but I'd like to focus on engine efficiency as opposed to power increases.

I'm assuming intake and exhaust mods are the primary cost effective way to increase mileage/efficiency, but perhaps you can suggest others.

In other words, I'm interested in those mods that are most cost effective in increasing gas mileage.

 

[Walter]

More air in the tires.

Keep the windows rolled up.

 

[bigwong]

Drive slower in the highest gear possible. But you're driving a porsche! I try to maximize my mileage, within reason, but I could have just bought a Prius for less money and (supposedly) get excellent mileage.

 

[Zatara]

Drive slower in the highest gear possible. But you're driving a porsche! I try to maximize my mileage, within reason, but I could have just bought a Prius for less money and (supposedly) get excellent mileage.

Yes, that and slow acceleration and high tire pressure and.... I get it. When I don't ride with friends I typically get 50 mpg on my Yamaha FJR 1300. When I ride with them and try to keep up, I'm lucky to get 38. I think we all know the techniques for better gas mileage.

As you say, the fun of having a Porsche, any Porsche, is driving it hard. Nonetheless, we'd like the option of getting better mileage when we can.

So... I'd like to know the most cost effective ways to accomplish this IN ADDITION to driving techniques.

Best I've done with my stock 2006 Boxster S, 3.2 L is 25 mpg.

 

[gasman1]

Guys, he said mods! Start with breathing mods: sports exhaust, free flow air filter, desnorkeling, and racing headers with sports cats. All of these mods will take a while for the ECU to readjust the fuel-air mixture, but you should get 10% or better improved mileage after a couple of weeks with a full set of breathing mods alone. A good ECU tune for your particular fuel (91 or 93 octane) and mod set will generally improve mileage another 5% given normal or highway driving. As far as maintenance goes: 5W40 Mobil 1 ever 5K miles, clean air filter every 10K miles, and keep tires inflated properly. Also take your car out for the occasional road trip or DE/AX track laps to keep it cleaned out.

 

[4by4]

Skinny rims with low rolling resistance rubber.
Weight reduction.

 

[Zatara]

Guys, he said mods! Start with breathing mods: sports exhaust, free flow air filter, desnorkeling, and racing headers with sports cats. All of these mods will take a while for the ECU to readjust the fuel-air mixture, but you should get 10% or better improved mileage after a couple of weeks with a full set of breathing mods alone. A good ECU tune for your particular fuel (91 or 93 octane) and mod set will generally improve mileage another 5% given normal or highway driving. As far as maintenance goes: 5W40 Mobil 1 ever 5K miles, clean air filter every 10K miles, and keep tires inflated properly. Also take your car out for the occasional road trip or DE/AX track laps to keep it cleaned out.

Yesss! Thass what I'm talkin' about. But... I'm new to this and Don't know diddly about the intake side of this. I'm assuming there's something about this on the mods page. This is a 987 so some of the original air intake mods have already been incorporated by the factory, compared to the 986... is that right?

At any rate, I'm looking at the most cost effective ways to accomplish this goal. I LOVE this car. Trouble is I'm driving it too much because of that. I just can't stop.

I have some curves on my local commute marked 10 or 15 mph I used to take on my motor cycle at 30, that I'm now taking at 40. Somebody STOP me.

 

[blackadder]

The cost of any mods will more than outweigh any fuel savings. Lets say one mod that costs $1000 (which is at the lower end of the scale for porsche mods) gives you a 5% fuel saving. To get your money back in 2 years time you would have to be spending $10,000 per year on petrol.

I would suggest that better fuel efficiency is a side benefit of performance mods.

 

[Dunebasher]

The cost of any mods will more than outweigh any fuel savings. Lets say one mod that costs $1000 (which is at the lower end of the scale for porsche mods) gives you a 5% fuel saving. To get your money back in 2 years time you would have to be spending $10,000 per year on petrol.

I would suggest that better fuel efficiency is a side benefit of performance mods.

And lets not forget because you have freed up more power and the car can swallow more air, when you push it hard you're going to see worse figures than before you changed anything.....but you will be going faster!

I'm new to this and Don't know diddly about the intake side of this. I'm assuming there's something about this on the mods page. This is a 987 so some of the original air intake mods have already been incorporated by the factory, compared to the 986... is that right?

The intake mods mentioned are not things the factory incorporated. De-Snorking is basically a mod that is almost free to do (check the articles section) and the factory intake and exhaust systems on almost all cars can be improved and Porsche is no exception. Anything that frees up more power will almost directly mean better fuel consumption, and mods to the exhaust and intake systems will allow the engine to breath easier and therfore the engine requires less effort to do the same amount of work compared to before the mods.....but you will not recoup your costs through better fuel consumption in the near future.

Using the highest octane fuel available and/or Octane booster can provide better fuel consumption.

A proven cost vs long run fuel saving is an LPG conversion, however I doubt the engine in this case is going to like it in the long run due to engines running on LPG running much hotter.

However I must say....Porsche....Fuel consumption.....US.....:hilarious:

Fuel consumption is not the first thing one thinks of with a sports car, but also as you live in the US your fuel is relatively inexpensive, yes it's gone up, but you are still lucky compared to most other places. I say before your fuel prices Stateside get up to European levels put the pedal to the metal!

 

[Jeff G in NE GA]

The cost of any mods will more than outweigh any fuel savings. Lets say one mod that costs $1000 (which is at the lower end of the scale for porsche mods) gives you a 5% fuel saving. To get your money back in 2 years time you would have to be spending $10,000 per year on petrol.

I would suggest that better fuel efficiency is a side benefit of performance mods.

I totally agree.

Driving technique - slower acceleration, lower speeds, conservation of brake use. Sounds like a Prius board. Did you ever see the Top Gear episode where a new V8 M3 got Better fuel economy around their test track than a Prius? The Prius was run as fast as possible, and the M3 just loafed along at the same speed (as the Prius). A dramatic demonstration of the effects of driving technique.

You could also buy an economy car and just drive the Boxster on weekends.

 

[balpo]

Really interesting topic.
I have softronic and on my daily commute route the softronic flash has yielded 0.3mpg increase. Car is otherwise stock.

The exhaust question is interesting. On my MR2 spyder - elimination of the cats in the header resulted in a 5% increase in mileage. Whereas, replacing the main cat with a high flow cat resulted in no change in mileage. So, it would be interesting to hear from Tomaz - who has tried both configurations in our cars.

 

[DaveN007]

I wear one of these while driving.

 

[K-Man S]

I wear one of these while driving.

Dave,
I thought you were the one who got out the industrial drill and bits and started drilling holes in everything, the floor pan, the frame cross members, the wheels, heck just about anything you could reach with the drill. As I understand it your gas mileage went way up due to the decreased weight, that is until you drilled extra holes in your gas tank, at which point your mpg went way down...

:hilarious:

 

[BadToTheBox]

Push it part of the way.:hilarious: