New hot rodder type
 

Hi Everyone,

I have been lurking on the site for a while and I thought I should post an introduction. I am Bob Esser. I am an engineer. I like interesting engineering challenges. I like fast cars. I like safe motorcycles (oxymoron?). I basically like anything with an engine. I usually track my mpgs for any vehicle, but, as much as a diagnostic as anything else.

I must admit, I don't like hypermiling and I don't think I will ever do it. I had a Mini Cooper JCW for a while. I tried laying off the gas for a couple of tanks. I did notice a 5% improvement in mpg, but, it was really unsatisfying to drive that way.

For hobby, I autocross my car. I used to do High Performance Driving Events when I had free time (before my son was born). I like driving sporty and technical.

I recently took a huge step backward in the mpg department as I moved from a MINI cooper JCW (28 mpg) to a BMW M3 (18 mpg). I had started a new job with a 90 minute commute each way (a couple times a week) and I found that my back/butt couldn't handle sitting in the MINI that long - the seats just didn't work for me in that driving cycle.

Revisiting the hypermiling and mpg topic, I like engineering challenges. So, while I don't intend to hypermile, I do like to modify my vehicles. If I can do so and improve mpg, that would be great. So, I can see myself doing mild things like underbody panels and partial radiator blockoffs, I don't anticipate boat tails and hypermiling experiments. (read as non-extreme engineering solutions, not behaviorial ones). By the way, if anyone knows where to locate 18" moon-eye type hubcaps, that would be great.

Bob

Also, at what point do I cease to be a 'new user' so I can post my fuelly in my signature?

Bob

5 posts

Welcome!
you might look at the posts in my sig.
You and I have similar ideas on how far we will go.....
(btw, all my mpg gains are with the climate control ON!)

Certainly air up the tires and think about upsizing on your next purchase.

Welcome. How are your fabrication skills? If you have fabrication experience and adequate tools for your tastes you might try an airdam (chin spoiler), side skirts, belly pan, defuser, rear wheel well skirts, and a flat trunk lid spoiler. with the exception of the wheel well skirts these are mostly low profile or "normal" looking mods. But to do them really well (read as effective AND attractive) requires thought and experience. All those mods interact with one another, so part off the work can be in the dialing in of the best effect, which is tricky or impossible with the low-grade measurement equipment we all have access to typically.

Welcome to the site. Good luck with your mods.

Welcome aboard !

It is possible to drive fast yet efficiently.

P&G at 80 mph works ust as good as it does at 60 ...
Each to their own though ...

Dude, seriously?
 

Welcome,

There are several BMWs listed in the garage. If your mileage results are that bad, it would make your ride the thirstiest Bimmer in the book. There are a few M5s listed that state a lower EPA rating, but evidently the owners couldn't be bothered to do more than just list their cars the one time.

If you're into elbows-out driving, I'll bet you're running some sticky tires. That's going to hold you back some.

Air control is your friend. The less of it actually banging into parts of your car, the better. Barring that, if you can shove it to the side once instead of having it bang and tumble and bang again, do that.

A driver unwilling to make compromises toward the goal of higher mileage is going to have very limited results. The M3 is an entertaining ride but really - how much of that capability can you use on your commute without getting lit up by the highway patrol? Shenanigans on the road = unpleasant introductions and giving your autograph to people you'd rather didn't have it.

If your car is on 18" alloys, will smoothie wheel discs even work? Gotta have that little rim for those clips to grab.

Open a garage page for your car. "M3" only tells us it's a 3-series with a gym membership. How old, what equipment etc.

yes, seriously.
 

Based on Fuelly, I am getting a bit better than typical on my car. The M3 is thirsty - no argument there, and it is sort of an anomaly in the BMW book because most of their offerings have fairly decent mpg.
'Elbows out'? not sure what that means.

The M3 has a partial underpanel on it from the factory. I think I can clean it up some, but, not much due to the exhaust and such. That said, I think I can at least put an airdam that is deeper and perhaps clean up some underside air near the front.

My fab skills are not great (for aesthetic parts at least). I would consider moon eye hubcaps and if I could make them look nice, I would do skirts.


As a rule, I don't drive like an idiot on the road, but, I do autocross, and I like to drive fast on closed courses - and then, I do use the capability.

I am very much a technologist, and I am sure that there are technological solutions. I do realize that behavioral changes will net very good results too. For me, hypermiling kind of sucks the joy out of driving, but, if behavioral was the only way, people wouldn't be on here putting extended tails on cars and such. Also, I like to mod and fiddle with stuff, so, mods seem the natural way for me.



I also am not sure if smoothies will work on the rims, but, it is worth trying. The M3 is the 2008 M3 Sedan, so, it has the 4.0 V8 (thirsty). It does have the fancy suspension, so, (I think) it is about 10mm lower from the factory. Unfortunately it is difficult and thus expensive to lower it and keep the electronic suspension, so, additional lowering may not be in the cards.

Bob

If you want to gain on the efficiency of the vehicle alone without ruining it then it's a combination of weight saving and aero improvement.

Aero improvement can be more involved as far as looks is concerned (potential ruining)

Best bet is lightness and reasonably narrower tires.

I strongly agree with adding lightness.

Bob

Looks like the same hot rodder type to me. ;)

:p

Hotrodder Mk2?
Mk1 mod 2?

Bob

Maybe use HELIUM to inflate your tires...and don't forget the spare (wink,wink)!

Sadly, no spare to remove. I religiously fill my tires with a minimum of 70% nitrogen.

Bob

...adding lightness (helium vs. air)

Hydrogen!!!

"Elbows out" = spirited driving, esp. autocross, where you get your shoulders and upper arms into the action for faster turns.

I think that may be more of a British term. I don't remember where I heard it first.

If you're not doing autocross really often and have easy access to a lift and air tools, you might do very well to round up a set of narrower steel wheels for some low rolling resistance tires. I say steel wheels because they have that little lip around the edge that clip-on discs will engage. Then you spend most of your time on the thriftier tires and save the sticky, expensive tires for when it matters, during events. The lift and air tools just means being able to swap the tires whenever YOU want, not at the convenience of some shop.

That V8 is a sweet mill. But it does churn through the gas, no question. I'm not familiar with them but maybe you could bounce this question around on the BMW forums too, I know there's technology-minded gearheads for every marque (with the possible exception of Kia) who have dug into their cars' engine management. You may just need to reflash the engine computer, or get your hands on a replacement one to switch in for your thriftier daily driving needs.

I'm pointing up my ignorance. I have no idea if there are anti-theft features built into a BMW computer that might prevent such swapping. Too bad if there is, swappability make converting the car from a track day athlete into a long-legged posh commuter a quick, click-click operation.

Swapping wheels is not a big deal - I do it for winter wheels already. One big problem though is fitting wheels over the brake calipers.

The BMW M engines rock. 4.0 liter V8 with a 8300 rpm redline! I used to love big torque from turbo'ed mid sized 4 cylinder engines, but, there is just something about the urgency of a high strung naturally aspirated engine.

There are definitely a few 'tuners' for my car and some will allow you to change the tune through the OBD port, so, it is definitely worth looking into. I know that the engine warm up cycle used to heat /light off the catalytic converters tends to be bad for fuel economy. The problem is that it is bad for the environment to have the warm up cycle removed. Not sure where I fall on that compromise. I am sure that there are other places in the tune to find extra fuel economy.

Bob

What is your commute ?

How do you drive ?

Honestly, I can't see much FE improvement coming from ecomodding the car.
It is already very much refined to be performance vehicle with a very big engine and such.

I tend to drive spiritedly once in a while, coming from motorbikes.
Thing is I have much more fun going flat out with a much smaller engined vehicle than I do allowing me to break the law once in a while with my regular car, not to mention the safety issues. And it's not even sporty !

So I seem to recall you're telling us that you use a M3 as a daily driver and that you don't break the law with it and that you drive hard on the track ?
Yeah, right !

Each to their own but an econo box on the side of the M3 is going to pay for itself in no time ...

Try P&G one of these days, it's much funnier than you think.

I like track racing, and I like commuting to save fuel. Two different ways to enjoy driving. I slowly got into hypermiling; it's too much of a challenge and requires too much attention to go all in at once with P&G.

Try coasting out of gear to known stops. Turn off the engine at long lights. Accelerate briskly without higher rpm to your target speed and get into high gear/low rpm to maintain. I am constantly challenging myself to maintain momentum through curves and turns, and timing traffic signals to minimize braking.

Spirited driving doesn't always have to be about all-out acceleration or rushing up to stops.

As I said, I don't drive like an idiot, but, I do keep up with traffic, which in DC can be 80 mph.

I had a motorcycle that I wish I hadn't sold (Ninja 500) and I plan on buying an older Ninja 250 very soon. The new bike will likely be the basis of more serious MPG efforts. (This will be my 'econobox')



I guess, it helps to look at it as hypermiling is a different sort of precision driving.

Bob

I was going to suggest spending what you might on another set of wheels/tires on a cheap commuter...but I couldn't do it. You already have to sit through a commute, you shouldn't have to punish yourself by giving up that BMW interior to do it economically.

I know DC driving. I grew up there. And yeah, there are places where 80 is what it takes to not get somebody up your tailpipe, shouting imprecations.

At this point, I'm out of suggestions.

At 80mph there are huge gains to be made in aerodynamics, but I doubt this is going to happen with a BMW, I certainly wouldn't do the mods.

If you go in the triple digits speed range you can get transonic flow which as we all know has much lower aero drag.

Why?

I guess because late BMW are already very much refined in this department and that aero is often a compromise that we, individuals, can very difficultly evaluate and alter for the better.

Modding an 80's econobox is far easier.

I have a long commute also so...
 

I played with my tire size untill I got a best case scenario at 75mph.
Not a hot rodder per say just going with speed of traffic mostly.
Lowering my engine rpm @ 70 mph untill I best used inertia and engine torque at that speed.
Now this resulted in a ride height difference of 1.75" so I installed a chin spoiler, and side skirts instead of belly pans. {those may have proved better not sure>}
Then I worked on aero by deleting the passenger mirror and folding back drivers side.
next I moved tail spoiler as far back as possible on the trunk
Next I added wheel disc covers.
Little things like a wiper shut off help little, but items like engine kill switch and push button start helped final effect by making P&G and engine off coast down easier and saved on motor mounts and clutch.
My POS can really coast engine off now and cleaning and relubricating drive line helped alot.

I hope this helps you some and happy motoring.

I've modded my Prius for better aerodynamics, one of the most aerodynamic production vehicles. There is plenty of room for improvement on his car. :rolleyes:

Just looked it up, the drag coefficient and it is .30. That is really not all that slippery.

Have you done any modifications so far? If you're monitoring temperatures and in regular driving, grille blocks should be in line, and can be tasteful.

I saw you mentioned the exhaust, but an underbody would be a great point to expand on. mcsrews was successful with his Q45 build, and my polycarbonate hasn't had an issue yet.

Rear wheel covers could be in line, but definitely more noticeable. Have you went through 65+ Vehicle modifications for better fuel economy - EcoModder.com for ideas while you start working on what you like from 100+ Hypermiling / ecodriving tips & tactics for better mpg - EcoModder.com

It will be a little while before aero mods will be more so beneficial than driving technique, but the DC commute will help. I found my FE wasn't so bad at higher speeds in the traffic, but I imagined it because we were such a cluster moving through the air.