[pdude]

Recently, I picked up my 'new to me' 2006 E90 325i. I'm coming out of the Honda world, and I was expecting an increase in fuel consumption, along with a major boost in driving fun/dynamics . Both have come true.

Still, I'm wondering if there are any mods, electronic or not that prove to be effective in the l/100km area. I'm about 25c/75h driving.
Thanks.

[DESI4life10]

Originally Posted by pdude

Recently, I picked up my 'new to me' 2006 E90 325i. I'm coming out of the Honda world, and I was expecting an increase in fuel consumption, along with a major boost in driving fun/dynamics . Both have come true.

Still, I'm wondering if there are any mods, electronic or not that prove to be effective in the l/100km area. I'm about 25c/75h driving.
Thanks.

You bought the wrong car my friendNaturally these engines do consume more fuel than other Japanese brands. I am not too sure what we can put in the car to increase l/100km consumption rate.

Maybe a performance intake Not too sure. Congrats on the car though.

[MechUT]

What Honda are we talking about? A 3 litre, 6 cylinder Honda Accord is only slightly better! The current generation of BMW inline-6 engines are actually pretty good with fuel economy, especially in this class.


What are you getting, by the way? I average 10l/100km, with a similar city / highway mix as you.

[pdude]

The Honda was a 4, so it was in the 6.5 range.
I'm actually happy with mine, it's 9.6, have not seen it over 10 just yet.
I was just wondering if there is 'something' I could mod, but currently it is what I was expecting. Love the power.
Some posts I've seen claim that a mod could help, but ppl mod their cars in a major way here, I don't think I'll be going to these lengths, mostly because of cash flow.

[nospleeny]

323 would be your answer if you still want BMW. It will cost you more in the end since you've already purchased your vehicle. I'd recommend you just enjoy the extra dynamics of your vehicle and don't worry about fuel consumption. Luxury vehicles never come with good fuel economy unless you drive a hybrid (which also doesn't make economic sense since they cost significantly more on the outlay).

In short... you got to pay to play.

[peanuboy]

I am already glad my N54 is doing slightly better than my old 20V1.8T which was a 4 banger!

imo, if fuel economy is very important to you, BMW is not your answer, even their Diesel models arent designed primarily on saving you fuel.

[nospleeny]

I drive a Acura TL right now still and this 335xi gets better mileage than my TL does... I came from a Civic back in the day, but as your lifestyle moves up, I hope your income does too.

[peanuboy]

Originally Posted by nospleeny

I drive a Acura TL right now still and this 335xi gets better mileage than my TL does... I came from a Civic back in the day, but as your lifestyle moves up, I hope your income does too.

Direct Injection in the N54 plays a vital role here I think

[2kaccordocoupe]

a cheap mod would be properly inflated tires

[paullo]

Lighter wheels/tires. Will reduce the unsprung weight of your car and if you get decent performance tires; reduce rolling resistance as well. By no means the cheapest mod, but definitely a gas-saver.

[MechUT]

Originally Posted by paullo

Lighter wheels/tires. Will reduce the unsprung weight of your car and if you get decent performance tires; reduce rolling resistance as well. By no means the cheapest mod, but definitely a gas-saver.

As long as they are not wider!

[paullo]

Originally Posted by MechUT

As long as they are not wider!

Not entirely; it depends on what resistance rating (tread pattern) the tire has. A wider performance summer tire is going to have less rolling resistance than a comparatively narrower all-season.

[zuluZero]

Mod your self, or at least your driving habits:

- reduce weight: don't carry around anything extra (unless car pooling). Don't keep your golf clubs in the trunk.

- reduce acceleration and braking: accelerate smoothly (no fun), but more importantly, avoid slowing down in traffic more than necessary, where you'll just have to speed up again.

- reduce speeding: your car will have an ideal RPM and speed range to travel at. Beyond that, your fuel consumption will increase. I'm guessing that it's around 110kph. Beyond some speed (say 120kph) you'll burn more fuel per klick.

- reduce idling: never ever idle, not to warm the car up, not to buy coffee, not even at a long stop light. Some lights are 2 figgin minutes long! It's seriously easy to push the start button.

- reduce drag: drive with the windows & sunroof closed, and keep your paint clean & waxed. A/C use can be less expensive than drag.

- reduce neutral coasting: your engine will use less fuel if you coast to a stop in gear than in neutral - many people don't realize this about modern cars

Personally, I don't care much about the cost of fuel - it's more the hate of getting screwed at the pump by a corrupt system, and having to stop for fuel when I'd rather just drive straight home for BBQ and read this forum

[paullo]

+1

Here's a link to some easy (and some are free) tips on better fuel economy.

[marcvtec]

Clean your car everyday and you'll save 10 bucks per tank.
-Road and Track Magazine vol. 138-

[spacedogg]

I would think about switching away from the stock 17" runflat tires setup to something lighter. The stock rims are quite heavy as are the stock runflat tires.

Cosmetically, 18" or 19" rims will look nicer, but you want to opt for a well constructed lighter 17" rim which is at least sub 18 or 19 pounds. You can get energy efficient tires which have less rolling resistance which will help. But usually their performance will be limited. Something narrow would probably better efficiency wise. So skip a staggered setup.

All this will reduce your unsprung weight and rolling resistance which will ultimately will help in mileage. However only expect a 1 or 2 mpg increase. Your investment will cost you about $1000 to $2500. So the cost benefit ratio for this mod is quite low and you will need to drive a lot to recoup your costs.

A well constructed intake may help. When I had my 325i people were saying the Gruppe M replica intake gave a couple mpg increase. If purchased on ebay it will cost about $400.

Your biggest increase in mpg will come from driving with care and a light foot over the gas. That alone can make a difference between 27 mpg on the highway and 36 mpg (doable on a 325i).

Do not coast in neutral as that uses more fuel than if you are in gear coasting. If you drive stick try to keep in gear as long as possible when coming up to a light.

Keep all your tires well inflated. Higher psi will also reduce rolling resistance. 36 psi or above would be best. Check the rating on the tires. 40psi might be ideal for gas efficiency but you may feel the ride a little harsh.

Do frequent engine oil changes. I would recommend doing them more frequently than is recommended by BMW as I've noticed my mpg go down when the oil is old. Keep the engine serviced...you may want to talk to a independent garage recommend some preventative maintenance such as coolant flush and tranny/diff flush (even tho BMW says it is lifetime fluid it might still be advisable)

[micinca]

Just Buy A Corolla, That Shit Save Gas A Lot

Its Bimmer!!!ok??!!
Enjoy The Ride Man,

[pdude]

Originally Posted by micinca

Just Buy A Corolla, That Shit Save Gas A Lot

Its Bimmer!!!ok??!!
Enjoy The Ride Man,

If I wanted one I would...

Anyway, for those interested, I got through my first tank of gas and I got 8.9 l/100km or 26.4 MPG. (25 city/75 hwy).
Much better than what I was expecting. The computer states something in the 11 range, but that's a little off and I think only the last 30km.

Gas used was Shell 91 in Canada.
Today I filled with Sunoco 93, in USA.

Later.

[Richwm]

Like the others have said light weight wheels and tires my 18" MT1's weigh 18 lbs each and I saw a 2-3 mpg gain I get 32 mpg at 75 mph and 34 mpg at 68 mph. Also if you are getting to 50k miles change your spark plugs also.