BimmerFest BMW Forum banner

Do you really save $$ on gas with diesel?

10K views 49 replies 32 participants last post by  kga1958 
#1 ·
Here in CA diesel costs 20 cents more per gallon then premium unleaded. If you compare the annual fuel costs of the standard 3.0 vs. 35d are they about even since the diesel has better mpg? Or does the price difference give the 3.0 the edge?
 
#2 ·
Simple math.

15,000 miles a year.

20mpg for the 3.0 avg; 750 gallons x 2.00 = $1500

24mpg for the 3.0D - avg; 625 gallons x 2.20 = $1375

But...the Diesel also gets to 60 in 7.2 seconds, versus the gassers 8 seconds...

and has more torque, and I suspect though i've not driven one, better performance around town...

Now...let's assume you drive like me:

30k miles a year, with a lead foot. I average 14mpg out of the 4.4i I have, in town, and 19 on the highway. So, overall a 17.5 mpg. Past experience has proven that even with a smaller engine, I"ll get very similar fuel economy, because i'm giving it the boot all the time...whereas, the V8 has enough power that I'm not *always* dogging it, just most of the time.

I'd expect real world mileage of the diesel for me to be about 22mpg or so. Highway would be more, in town a little less, but 22mpg is probably a good figure.

17.5mpg (V8) at 30,000 miles/year = 1714 gallons x 2.00 = 3428 At $5/gallon its 8570 for the gasser

22mpg (diesel) at 30,000 miles/year = 1364 gallons x 2.20 = 3000. at $5.20/gallon is 7093 for the diesel

But...the new diesels qualify for a tax rebate of $1800.

So...yes...the diesel will probably save you money, especially over the long haul and if you do a lot of driving. For me, the extra mid-range torque would negate the need for a thirstier V8, with little loss of overall performance. The tax credit is nice. And when fuel goes back up, the difference will increase dramatically.

Why don't I have one? Can you see putting 30k on a new car in the first year? The depreciation would kill me. I'm looking forward to a couple years from now, when the diesels are available as CPO vehicle, and I'm ready to upgrade from my '04 4.4i.
 
#33 ·
My calculation is a bit different. I (and probably most who buy an X5) pay the Alternate Minimum Tax (AMT) so I don't qualify for tax rebate (bye bye $1800). I negotiated both X5 3.0 and 35d and the bottom line cost difference after taxes between a X5 3.0 and 35d was over $2200 (considering current rebates of $2500 back on 3.0 and $4500 on 35d). I drive about 15,000 miles per year and figured $600/year fuel savings based on my driving so basically a four (4) year payback . That assumes diesel and premium gas stay at parity (though within the past year or so I have seen diesel going for as much as $1/gallon above premium which would obviously eliminate any mpg benefit )

I plan on keeping this vehicle but after 4 years BMW maintenance is up so I have to pay for Adblue . I did a quick search and it seems like the stuff goes for about $15/half gallon. BMW 35d requires 6 gallons of Adblue ,so theres another $180 every 11,000 miles. Thats assuming I can do myself and don't need special BMW Adblue stuff ,otherwise you can probably double that cost. (oh if you don't refill at 11,000 the X5 35d will not start. Thats right-NO GO!! ) . The Adblue system is a whole other fluid system unique to the 35d. Thats more things to go wrong. I understand 6 gallon Adblue tank takes some room from luggage space in the 35d . Also the Adblue fluid freezes below 15 degrees so need to run a heater when it gets cold. There is also increase maintenance on injectors and other parts with diesel. Considering above seems to offset most of any fuel savings. So while x35d mpg numbers look great on paper its just because your paying for it elsewhere (higher up front cost, higher long term maintenance costs, potentially higher diesel fuel prices , etc.)

Then there's some additional factors I considered: You can't always find a low sulfur diesel station in some areas (e.g. we recently looked in three stations in remote Pennsylvania with no luck). The x5 35d has been reported to be noisier than x5 3.0 and i've also heard of occasional hesitations with the diesel.

I know X5 35d beats in torque and performance (something like 7.2 vs 8 seconds ) . However in my opinion ,given the the above considerations, makes the economics and ultimately the decision between 35d and 3.0 closer than suggested by some in this forum. If I'm incorrect or mis-stating anything please let me know. thanks

Simple math.

15,000 miles a year.

20mpg for the 3.0 avg; 750 gallons x 2.00 = $1500

24mpg for the 3.0D - avg; 625 gallons x 2.20 = $1375

But...the Diesel also gets to 60 in 7.2 seconds, versus the gassers 8 seconds...

and has more torque, and I suspect though i've not driven one, better performance around town...

Now...let's assume you drive like me:

30k miles a year, with a lead foot. I average 14mpg out of the 4.4i I have, in town, and 19 on the highway. So, overall a 17.5 mpg. Past experience has proven that even with a smaller engine, I"ll get very similar fuel economy, because i'm giving it the boot all the time...whereas, the V8 has enough power that I'm not *always* dogging it, just most of the time.

I'd expect real world mileage of the diesel for me to be about 22mpg or so. Highway would be more, in town a little less, but 22mpg is probably a good figure.

17.5mpg (V8) at 30,000 miles/year = 1714 gallons x 2.00 = 3428 At $5/gallon its 8570 for the gasser

22mpg (diesel) at 30,000 miles/year = 1364 gallons x 2.20 = 3000. at $5.20/gallon is 7093 for the diesel

But...the new diesels qualify for a tax rebate of $1800.

So...yes...the diesel will probably save you money, especially over the long haul and if you do a lot of driving. For me, the extra mid-range torque would negate the need for a thirstier V8, with little loss of overall performance. The tax credit is nice. And when fuel goes back up, the difference will increase dramatically.

Why don't I have one? Can you see putting 30k on a new car in the first year? The depreciation would kill me. I'm looking forward to a couple years from now, when the diesels are available as CPO vehicle, and I'm ready to upgrade from my '04 4.4i.
 
#3 · (Edited)
You can look at the mathematics of it as demonstrated above.

There are simple advantages of diesel. You get substantially longer range between fillups. The midrange torque is unparalleled by any petrol from BMW, including the M5. It has 580Nm of torque versus the V10's 520Nm. This makes the vehicle extremely flexible in any situation. You are being "green" for the environment because it emits less CO² than any other X5 model (okay, the xDrive30d in the EU emits 3 g/km less, big deal). In Virginia, diesel is usually a modest $0,08/litre more expensive, but I have seen places where it is almost on par with premium petrol.

Honestly, I don't understand why anyone gets the 3.0si model, maybe someone can explain this to me. Just my ***8364;0,02.
 
#4 ·
You can look at the mathematics of it as demonstrated above.

There are simple advantages of diesel. You get substantially longer range between fillups. The midrange torque is unparalleled by any petrol from BMW, including the M5. It has 580Nm of torque versus the V10's 520Nm. This makes the vehicle extremely flexible in any situation. You are being "green" for the environment because it emits less CO² than any other X5 model (okay, the xDrive30d in the EU emits 3 g/km less, big deal).

Honestly, I don't understand why anyone gets the 3.0si model, maybe someone can explain this to me. Just my €0,02.
I waited two years for the diesel. The gas 3.0 didn't have enough power and the 4.8 uses too much fuel.

Craig
 
#5 ·
When gas was $4 plus last summer, diesel was about $0.75 per gallon more expensive in the midwest. That relationship is wildly unpredictable. Also, there is the extra up-front cost of the diesel motor after the tax credit--what, $3,000 net? If you ignore the discounted value carry-forward (when resold, the diesel will return some if not all of the extra cost, but you are deprived of that value in the interim), it could take years/ many thousands of miles to break even. The BMW 6 is a great motor generally and moves the X5 well, at least in manual. I think there is still a market for the 6. When my 08 3.0 is ready to be traded or sold, I will look at the diesel, but it is not clear that I would get one. I would never get an 8. Further, I am not a soccer mom.
 
#7 ·
SoCal diesel prices waaaay down

I saw today in LaQuinta at a Chevron on Hwy111 that diesel was $2.13 a gallon (may have been $2.18...I was driving by) which was lower than regular unleaded, unleaded plus AND premium. I think Premium was $2.39, plus was $2.29 and regular $2.19.

At least this week, everyone who runs the approximate breakeven point for making a diesel pay off will have a different outcome.

Peace
 
#11 · (Edited)
Here is the little curve ball on the diesel speculation
We might start getting more demand for diesel in US and the refineries will be producing more of it, hense, the price likely to be lower than 93
Regarding China:
Well, they needed a lot of diesel to power their electric generators for Olympic games
They did cut back a lot and i'm sure they wont need it as much in the near future

For your "Hyundai" comment:
It will not just save you money, it'll give you better performing car that takes less trips to gas stations while throwing less carbon into the air
Isnt it a nice feeling?

P.S. Oh, try towing with 3.0, definetely not as good as with 35D
 
#12 ·
The fuel and cost savings from owning a diesel will be small. When you look at it as a percentage of acquisition cost, almost trivial. I've heard some stories that this will change as our involvement in 3 wars diminishes--not sure how much I believe that.

Diesel vehicles are about much more than cost savings. Perhaps the biggest reason we have them in North America at all is because consumers wanted a choice. Diesels will not be a profitable segment in the near term, or possibly even in the medium term.

Diesels do provide a good interim step as the world weans itself away from fossil fuels. And in a world where governments are beginning to legislate how efficient passenger vehicles have to be, diesels serve a compelling purpose for manufacturers looking to increase their corporate fuel economy averages.
 
#14 ·
The fuel and cost savings from owning a diesel will be small. When you look at it as a percentage of acquisition cost, almost trivial. I've heard some stories that this will change as our involvement in 3 wars diminishes--not sure how much I believe that.
I still think that an $1,800 tax credit and $500-1000 per year (basically a car payment) in gas savings can be significant. When you combine that with getting a vehicle almost as powerful as the 4.8 for about $5K cheaper, I think the cost-benefit equation is a no-brainer. Am I missing something?

Diesel vehicles are about much more than cost savings. Perhaps the biggest reason we have them in North America at all is because consumers wanted a choice. Diesels will not be a profitable segment in the near term, or possibly even in the medium term.
What does this mean? Not profitable for dealers? No offense, but why would consumers really care about that? And why do you think they'll be less profitable than other vehicles?

Diesels do provide a good interim step as the world weans itself away from fossil fuels. And in a world where governments are beginning to legislate how efficient passenger vehicles have to be, diesels serve a compelling purpose for manufacturers looking to increase their corporate fuel economy averages.
 
#13 ·
The 3.0 in sport mode tows pretty well. I tow a race car in a covered trailer to races around the Midwest, two motorcycles in the same trailer out west, and also a sailboat on a dual axle trailer. The X5 does a better job at that than my old Jeep Grand Cherokee with the small 8. The sport mode moves the engine into a higher torque range across the gear spectrum. The standard automatic shift points are set for good CAFE numbers. But, yes, of course, the diesel will do that "better." The point is that the 3.0 is pretty good.
 
#17 ·
Diesel is cheaper than regular gas! For the first time in a great while I noticed on a Union Station price board they were selling diesel for less than gas. The cost was $2.31 for diesel and $2.39 for regular. If this trend continues it will make even more sense to get a diesel. Since I currently do not have a diesel but am looking at a Jetta Sportwagon (45 mpg) as a possible replacement for my X3, I have been watching the prices. Usually they have been around the cost of premium, but lately have been less and now are the lowest I have seen. This is in the Sunnyvale California area at the station on Fremont and Highway 9 (DeAnza Blvd.).
 
#19 ·
Lowest diesel price here in Omaha is now $1.85

Getting 20.5 mpg in town, 26 mpg highway driving my X5d. I previously owned a 2001 X5 3.0i and the power was much less - terrible acceleration compared to the diesel. There is no comparison of the 6 gas vs 6 diesel IMHO. I drove the X5 V8 at the BMW Performance center in SC and I must say the diesel is every bit if not more powerful.

I would assume towing would be a hassle and with constant downshifts on hills with the 3.0i, but effortless with the 3.0d.
:thumbup:
 
#21 ·
Diesel in my area, Sierra foothills, near Sacramento is .20/gal. less than premium. Diesel is the only way I'd get an X5. I'm looking at maybe ordering one within a week or so. Heard conflicting info on whether I can get the $4500 discount if getting car after 8/31 by ordering. Any input? Thanks!
 
#22 ·
Funny, that's how I describe my location too.

Have you ordered yet? There really isn't much time between 8/31 and the 2010 arrivals. Indeed, I had heard that 'early to mid August' is when they start 2010 orders!

Mine is inbound, should arrive within a week or two. Initially the dealer was doubtful it would make the 8/31 cutoff. They were able to convert one of their 'dealer stock' orders to mine. It was ordered on July 8, and was out of manufacturing on 7/23!!!

Initially, my plan was to just see what transpired- if it missed the 8/31 day, and they wanted $4500, I would have said "Oh? Really? I've decided I want a 2010, lets order THAT instead!" No need for that now....

I've got to think that BMW would be insane to effectively raise the prices on the last month of the 2009 MY by $4500. One might envision even more trunk money. The other possibility is killer lease terms to let dealers move this last bunch...

If you want to compare notes on dealers, PM me we can chat...

GL

A

PS Fuel cost is really low on my list- I am more 'irritated' by low mileage,plus the torque on the diesel is amazing- wonderful driveability.
 
#23 ·
I forgot to add... if they can convert one of their next cars to your specs, they can make it a Spartanburg PCD delivery. It would likely be ready Sept 6-9. BUT- you actually "buy" the car a week earlier at the dealer in CA. So it would technically be sold prior to 8/31. That was my other back up....

:)

A
 
#24 ·
I'm probably one of very few, if not the only one, to like the BMW diesel engine enough to own both x5 35d and 335d. I've had the 335d since early March (fabulous vehicle) and I just traded my wife's 07 Volvo XC90 3.2 for a demo X5 35d with only 26 miles. I got a very fair value for the XC90 and the X5 for $7k under invoice (yes, $7k under invoice! - only because the car was officially put in service back in Feb. when there was a special demo program giving $2.5k to dealer) - I could not resist that. Have I mentioned that I love the BMW bi-turbo diesel engine?...:)
 
#27 ·
The diesel model costs $3-4k more than the 6 cyl model.

From what I have read, diesels/hybrids really don't have a payoff for several years and close to 75k miles.

If you lease a diesel, there is no payoff.

If you trade a 14MPG 5 year old X5 in for a diesel model, you just plunked down at least another $30k for a new car to get better mileage. Does not make sense from a savings perspective.

To me you have to look at the total vehicle cost including finance and operating costs.

It is rediculous to me to by a $60k truck because it gets 5 more MPG.

Don't get me wrong. I think diesels are great. But like Hybrids, they make the most sense from an economical standpoint when they are in $15-$20k cars.
 
#28 ·
The diesel model costs $3-4k more than the 6 cyl model.

From what I have read, diesels/hybrids really don't have a payoff for several years and close to 75k miles.

If you lease a diesel, there is no payoff.

If you trade a 14MPG 5 year old X5 in for a diesel model, you just plunked down at least another $30k for a new car to get better mileage. Does not make sense from a savings perspective.

To me you have to look at the total vehicle cost including finance and operating costs.

It is rediculous to me to by a $60k truck because it gets 5 more MPG.

Don't get me wrong. I think diesels are great. But like Hybrids, they make the most sense from an economical standpoint when they are in $15-$20k cars.
I agree that it is not wise to buy a $60k vehicle purely because of small gain in MPG. I do think, however, that it may make sense to buy a diesel vehicle for its performance (power/torque), and in case of X5 35d - its performance well exceeds the 3.5 gas version while x5d currently costs less than gas x5 6 cyl. Better fuel economy is just an added bonus for me. I disagree that diesel engines only makes sense in less expensive vehicles. You should test drive 335d and x5 35d to understand.
 
#29 · (Edited)
We owned a 2001 X5 4.4i and loved it since we had it built, until it was totaled earlier this year. BUT...

We live in the country about 50 miles from the nearest Costco etc.. On a good day our old X5 would make that run on cruise control at roughly 20 mpg. The 35d I test drove did the exact same run at 27 mpg! The majority of this run is on hilly 2 lane 55 & 60 mph roads. About 1/3 is on a at 70 & 65 mph 'freeway'. This type of driving comprises 80-90& of our annual miles. The remaining 10-20% is short trips to local stores etc. where the diesel mpg still beats all other X5s.

Our old X5 was a serious tow vehicle. We regularly hauled a couple of tons of gravel, road base etc. in our HD utility trailer (rated at 5,000lbs). We needed a replacement with all the refinement and towing power of the X5 but with better mileage.

The bottom line is that, we would not have considered buying another X5 if BMW had not offered a diesel. Given the $4,500 discount, $1,800 tax rebate, etc. The initial cost of the X5 35d is actually below ALL OTHER X5s. So diesel fuel could cost close to 35% more than premium gas (for the entire life of the X5) and we would still break even :)

Funf Dreisig

p.s. the only serious alternatives were other German clean diesels: MB ML320 BlueTec, Toureg, etc.
 
#37 ·
1. The 'performance' aspect is not reflected accurately in a 0-60 spec. At least when one looks at 6.2 versus 7.0, the uninitiated think it is virtually a tie... but the actual fact is that when driving you are more likely to simply need to maintain 65 up a steep grade, or run 55-75mph to pass- THAT performance metric is hard to quantify, and is the root of the driving experience. IMHO.

2. I suspect that in a few years it will be possible to program the DME to defeat the 'out of urea' interlock... just saying...

3. As Funf says, there will be lower prices for fluid that works just fine- for those that need the comfort of a BMW label, it will cost you.

A
 
#39 ·
Yes, the price sure can varry from station to station so one has to chop around. Gasbuddy.com is great for that. On average, diesel is running slightly cheaper than premium, here in Little Rock.
 
#41 ·
There is no need to torture yourselves over "payback!" With manufacturer incentives and/or tax credits factored in, and probably even without those, it is very probable that a high percentage (if not all) of the extra cost paid up front for a diesel motor will easily be returned at future trade or sale time. I have traded by 08 X5 3.0 for a ' 10 VW Touareg diesel, and having now experienced 400+ ft/lbs of torque and 28 mpg @ 80 mph, I would never go back to a gas motor.
 
#42 ·
Forget about the increased fuel economy or cost savings... the X5 35d is a better overall vehicle than the X5 3.0si. That engine is just about perfect for the X5's mission.

The only downside is a slight lag during initial throttle tip-on. I'm replacing out 3.0-liter with a diesel in 18 months.

- Mike
 
#43 ·
I've been driving a 2009 X5d for about two months, 1600-some miles on the odo now, and agree completely with the pro-diesel posts. Mileage: 21-22MPG in town, 26-27MPG on highway trips. The available torque is remarkable and I give a +1 to the post above about not needing to downshift when keeping constant velocity on an uphill road. Handling with the 09 Sport Package (includes Adaptive Drive) is remarkably good for a 5000 pound vehicle. It's not a 3er, but my family situation needed a vehicle to haul four people and a 50 pound dog, or, 4-5 kids to an out of town soccer game. There's not another vehicle that offers the same combination of interior room for five + a large internal cargo space, strong acceleration, great handling for its size, and remarkable fuel economy considering its mass. You could call those needs a "compromise," but the X5d is one heckuva way to define that word. The overall package is impressive.
 
#44 · (Edited)
I give a +1 to the post above about not needing to downshift when keeping constant velocity on an uphill road. .
I've said it a few times, so I'll try to limit myself after this one, but it really is amazing to me how the diesel can accelerate going uphill with minimal downshifting. The V8 is certainly faster by the stopwatch, but it needs to get the RPMs up to match the diesel under load.

As long as it is as reliable as the gasoline engines, I'll be happy if it has the same operating costs as the 3.0 gasoline engine.
 
#45 ·
In my area - diesel prices vary widely, but I have been able to find it readily at about the same price as Special Unleaded. I drive mostly local, and I am getting about 21mpg versus the barely 14mpg I was getting on my BMW 4.6. This car has similar power to that, but is getting 50% more MPG. So Diesel wouild have to be pretty high versus super for me not to think of this being a better alternative. Sure there are more fuel efficient vehicles, but I wanted a BMW and an SUV so for me this has been just great. I do think the car is louder than the gas version - but I kind of like the sound of it.

For those people in search of the cheapest diesel prices in their area, this site has been helpful:

http://autos.msn.com/everyday/GasStationsBeta.aspx
 
#48 ·
We are in the midst of selling our 08 4.8i and replacing it with a 35d.

We put about 32000 km per year on going back and forth to our cottage. Recently I did a pretty extensive analysis of the cost benefit of the diesel vs the V8 and talked myself out of the diesel on cost basis alone.

When I was about to purchase the 35d out of my own pocket the savings were negligable once all the costs were in. I think I estimated it would only save me about $200 a month overall. Hardly worth it.

Then my company offered to buy the vehicle for me and it became a no brainer.

A buddy has a 35d and routinely gets 1000km out of a tank on the highway and around 800 in the city. This is in comparison to our 4.8 which on its best day gets 560 on the highway and 420 in the city.

I love the V8 in the 4.8i and if I could afford to I'd keep them both and leave the M3 in the garage all winter. It won't be much of a hardship to drive it until I sell it though.

But at the end of the day the fuel savings alone wouldn't have convinced me to buy it.

I am really looking forward to the 35d, which hopefully, I'll pick up tomorrow evening. It has a few more options than our 4.8 (ones that I have in the M3 but not in the 4.8) so it will be nice to have the comfort access, nav and the sport package (beefy steering wheel).

Comfort access is one of those options I would have never ordered but my M3 had it anyway (no choice Canadian spec comes with it). After a year and a bit with it I really notice not having it on the 4.8. I'm forever leaving the key in the ignition and walking away from the vehicle.
 
This is an older thread, you may not receive a response, and could be reviving an old thread. Please consider creating a new thread.
Top