new car - which engine?

January 31, 2009 8:01 AM

Buying a new car: Is it reasonable to spend 1500$ on a more powerful engine?

With a powerful engine, I could probably save 30 seconds every day on my way to work.
On longer trips, I might even save 30 minutes.
Fuel consumption is just about the same.
I don't plan to move heavy objects or pull caravans.

Are there other reasons I am missing here?

posted by mitocan to shopping (33 comments total)

With a powerful engine, I could probably save 30 seconds every day on my way to work.
On longer trips, I might even save 30 minutes.

Unlikely. Most cars sold today will be perfectly able to drive the speed limit with the smallest engine they are sold with. Bigger engines give you faster acceleration and slightly better maneuverability, but your top speed is dictated by law rather than your engine.

Drive the car with the normal engine and the more powerful engine. If you can afford both, buy the one that you enjoy driving more.
posted by b1tr0t at 8:09 AM on January 31 [1 favorite]

How are you coming to the conclusion that a more powerful engine would save you travel time? Unless you're comparing an engine that can literally not perform at the speed limit to one that can.
posted by odinsdream at 8:09 AM on January 31

When you say that fuel consumption is about the same, whose measurements are you using? I would do some research. It stands to reason that a more powerful engine will suck down more fuel.

That said, I'd go for a more powerful engine just, cause, ya' know, it's more powerful. Manly, you might say Are you a guy?)
posted by InsanePenguin at 8:17 AM on January 31

Can you explain how you came up with those numbers? The only thing I can think of is that you will be accelerating faster from 0-to-speed-limit with a more powerful car, so all your time will be saved during acceleration.

I assume it can't be about top speed, since probably ever car built in the last several years can easily do 100mph.

Say you make $50/hour, that's about 42cents for 30 seconds, or 84 cents of your time saved per day making 2 trips to work. After 1700 trips you would have saved the $1500 extra you paid. Although your not really saving money, you're saving time...but time = money.
posted by Sonic_Molson at 8:20 AM on January 31

On longer trips, I might even save 30 minutes.

This is a flawed argument. You may accelerate slightly faster, but there is nothing stopping you cruising at 1mph faster in the less powerful engined car. It doesn't justify anything and only saves you any time at all if you drive the car absolutely as hard as it can go at all times. You could brake more aggressively in the less powerful car and get the same time savings, or cut yellow/red lights a bit finer. Unless you are racing, this logic does not work at all. It sounds to me that you want the bigger engine but need to try and make it seem sense logically to you (or your SO?)

Now, I'm no hippy, but unless you are going to tow something or drive very hilly terrain, there really IS no justification for the larger engine if the first is powerful enough to make the car usable for your needs.

So really you are looking at this in the wrong way. It really is as simple as this:

"Can I afford the bigger engine?" Yes/No (see below)

If the answer is yes, then "Will it increase the resale value of the car?" or "will I enjoy the car more with a bigger engine"? If either are yes, then get it.

If fuel consumption, extra insurance and ultimate cost are not factors, those are your only considerations except possibly cost of maintenance if the bigger engine is more to service (ie a V8 often costs more than a comparable V6 as it has more spark plugs, leads, etc).

More powerful engined cars are more relaxing to drive and enjoyable to own. The only thing stopping me getting the fastest version of any car I was considering would be cost of ownership (resale, insurance and servicing) and practicality.
posted by Brockles at 8:22 AM on January 31 [1 favorite]

A more powerful engine may be more fuel efficient than a small one if the result is that it doesn't have to work as hard. A small engine that has to work hard can be less efficient than a large one that doesn't have to do much. Transmission gearing plays a big part, too.

So if find yourself having to constantly thrash your engine during your commute, a bigger, more powerful engine (assuming the transmission isn't getting in the way) might result in greater fuel economy and definitely would lead to more effortless transport.
posted by pandanom at 8:24 AM on January 31

But it won't get you there any faster, unless you commute on a racetrack or an otherwise empty road with no cops.
posted by pandanom at 8:25 AM on January 31

How could anyone have possibly answered this question without knowing what models you're looking at?
posted by Zambrano at 8:29 AM on January 31

I think the deal with bigger engines is not necessarily top speed (well it may be, but its a moot point because it'll be something like 110 in the smaller one vs 125 is the larger) but largely acceleration. You'll use it on a highway to pass someone, or to accelerate down the entrance ramp. Not really much else. For residential driving you'd probably detect no real difference.

Of course, when you use it to accelerate at a faster pace, you almost definitely will use more gas.
posted by jourman2 at 8:32 AM on January 31

I would like to hear the reasoning that led you to believe a bigger engine saves time. Also, I would like to know why you think fuel consumption is about the same.
posted by Dec One at 8:34 AM on January 31

It's been my experience that sometimes hitting the accelerator is a better way to get out of a bad situation than hitting the brake (as long as you decide which to do fast enough). When that's the case, then the faster you can accelerate in a controlled fashion, the better.

Whether that's true for anyone else or not, there are just times (passing on a two lane road with oncoming traffic, merging onto a busy road, etc.) when it's very useful to have additional horsepower you can reach for, even if you don't use it much on a day to day basis.

All other things being equal, I'd spring for the more powerful engine.

(Of course, I'd also spring for the radar detector, too :-) )
posted by nonliteral at 8:36 AM on January 31

For example see this tool which compares of the V4 and V6 in toyota camry - your top speed/acceleration will increase due to expanded horsepower, but you fuel economy certainly goes down.
posted by jourman2 at 8:37 AM on January 31

YIt's worth noting what more powerful means - torque, horsepower? Take your most gear-headed buddy (or my ex-race driver dad) to the showroom and have him look at the torque/horsepower/gearing ratios. He can give you a good explanation of whether that particular engine is going to give you more oomph when driving in your usual conditions.

Personally, I always go with the more powerful engine. Amply powered cars are more fun to drive and respond more quickly. For me that's worth the extra cost.
posted by 26.2 at 8:39 AM on January 31

Theoretically, properly driven, the larger engine will last longer. Why?

Engine wear increases with load. Say Engine A need 75% of it's max power to handle the driving requirements. The larger Engine B, being more powerful, only neeed 45%. Thus, Engine B is working much less, suffers less wear, and lasts longer.

Note: For this to pay off, we're talking tens of thousands of miles. See Bus and Truck engines, which are often overpowered for their average loads, but easily last 500,000 miles with basic maintenance.

If you are intending to keep a car for many, many years, a V6 is likely to suffer less wear than a faster revving V4 moving the same mass.

BUT

You have to drive the same way. If you accelerate faster and travel faster -- in other words, you use the bigger engine at 75% capacity, rather than the 45%, then it's going to suffer the same wear.

Practical Reason: If the smaller engine offered has a history of problems -- see the Quad 4 engine as one recent example. Here, the larger engine pays off in reliability. Note that the converse could be true, the smaller engine may be rock solid, but the larger one a problem child.

Practical Reason #2: If you hate the performance of the smaller engine, you'll hate the car. If you hate the car, you don't take care of it, it falls apart, and you buy another car, which costs *a bunch of money.* Don't do that -- if you put the pedal down on the smaller engine and you don't like how it merges, you're just going to abuse it and kill it.
posted by eriko at 8:46 AM on January 31 [1 favorite]

You will not save time, unless you live in Australia's outback - it is not only you on the road. (Even if you do not consider the legal speed limit - you have to travel at the rate of traffic around you)
You will use more gas.
You will enjoy better acceleration (especially if you get a manual or 'trip-tronic' (fake manual shift) transmission)- but that may not be a great thing if you get mad occasionally (;-)).
You may get more speeding tickets.
As others have noted - with better acceleration you will definately enjoy your car more.

I bought a few years ago - sedan-type car, with 230hp... Other than the fact that I can touch my head to the sunroof (if closed), I love my car - the acceleration is awesome... ;-)
(and I did not even get the sport package)
posted by jkaczor at 8:52 AM on January 31

Practical example from my own experience:

I drive approximately 280 miles to visit my parents. I've done this maybe 4 times a year for 6 years (so let's say 25 trips each way, or 50 in total).

In my old 1.1 litre Fiat Punto the trip took 4.5 hours - with no holdups this time was consistent to within about 10 minutes. I tend to drive 10-15mph over the limit on UK motorways - technically illegal, but almost everyone does it (still no excuse of course).

In my more recent Rover 420 (2 litre turbo diesel) the trip still takes 4.5 hours, unless I use the fact that the larger engine allows me to exceed the speed limit by a greater margin (I don't).

These are motorway (freeway) journeys in light traffic. For city driving or on winding, rural roads, or roads with a lot of steep gradients, a car that can accelerate quicker will give you a time advantage over a smaller engine. But really you're not going to notice unless you're driving a really long way in those conditions, and that's not particularly common, except maybe in the mountains. But it's not sensible to drive like a rally driver, using every ounce of acceleration to shave seconds off a journey - that's getting pretty close to reckless driving. And if your reason for wanting a quicker journey is to save money, it won't - accelerating harder is an excellent way to use more fuel.
posted by le morte de bea arthur at 8:54 AM on January 31

Someone (I think it was Colin Chapman) has a well-known comment to the effect that the faster you can accelerate the safer you are. Chapman was an engineer and he meant by accelerate "change the velocity vector" so for him engine power, braking and steering were all ingredients in active safety - the ability to get out of situations you want to get out of.

There are times when having the (heavier) more powerful engine will compromise handling. Some of the early V6 Honda Accords had this reputation, and some Audis do too. There are also cases where the top-tier engine is overkill and is there only for bragging rights.

Consider your situation. If you spend your time in mannerly traffic with few white-knuckle moments (e.g. driving in coastal Oregon) you probably don't require the top engine. Most modern cars these days have ample power for routine driving. If you have a short merge onto a fast highway, get all the power you can. I don't drive well in icy conditions, and if I am on very slick roads a lot of power seems harder to modulate.
posted by jet_silver at 9:00 AM on January 31

reasonable depends much more on your circumstances than those of the car. sure, what it does to resell values may be of interest and it's a shame you didn't indicate the kind of car you are considering but $1500 more is an entirely different proposition to someone making $50k than it is to someone making $300k. so what's your debt situation? is this financed? how much do you usually save per month? how much would $1500 extra hurt you in reality? are you financing this car? ask yourself those kinds of questions. it's already clear you want the bigger engine, the question is not about that.
posted by krautland at 9:24 AM on January 31

Are there other reasons I am missing here?

The most important reason of all ---- "Vroooom, vrooooooooooom!"

(i.e. Driving a car with excellent acceleration is *fun*.)
posted by tkolar at 9:44 AM on January 31

Alternate takes-
1- Because you are even thinking about it, I'd say get the bigger engine. Otherwise, every time you are driving and the car doesn't have the power you are looking for, it will disappoint you.

2- $1500 will cost you $25 a month if you take a 5 year loan.

3- Higher level models usually hold their value better- especially if it's a relatively inexpensive car that sells well. Check out the used car ads. For example, look at something like the Pontiac Grand Am. This is a car that you could get loaded up for $20something, or you could get, at the end of the model year for a base model, for like $9000. Those cheap cars are a dime a dozen in the used market, the nicer models are both rarer and more sought after.

Besides that, MPG *can* be better for the reasons mentioned above. I've personally experienced this in the last three cars I've owned. This is under basically the same driving patterns:

1- 1990 Dodge Spirit, 3.0 V6. Averaged 25.
2- Ford Contour, 2.5 V6. Averaged 23.
3- Grand Prix, 3.8 supercharged V6. Averages 24.

Now, the Grand Prix is a way larger and heavier car, and if you correct for weight, it gets the best mileage. Interestingly, my results don't correspond with the EPA's MPG tests. 1 and 3 exceed the MPG ratings, the Ford barely met them. I came to the conclusion that, at least for my driving style, the more torque, the better the MPG.
posted by gjc at 10:17 AM on January 31

A more powerful engine may be more fuel efficient than a small one if the result is that it doesn't have to work as hard.

i'd like to see some (non-anecdotal) evidence for this.
posted by klanawa at 10:49 AM on January 31 [1 favorite]

also, the single-biggest factor in fuel economy is your personality. if i drive conscientiously and use cruise control, i get >24mpg in my tacoma (with a v6, big tires and 4wd). if i drive normally, i get a number closer to the EPA rating (~20). if you're concerned about shaving 30s off your commute on the way to work, you're probably an aggressive driver and any talk about fuel economy is pointless because you're going to be wasting gobs of fuel no matter what you buy. an efficient car driven inefficiently is an inefficient car.

that said, i bought a tacoma with a v6, because the 4 was going to be a bit sluggish frustrating. by driving judiciously, i can make up for the ding in fuel economy, be safer and prolong the life of my engine.

which reminds me, i'd like to see some evidence for this too:

properly driven, the larger engine will last longer.

posted by klanawa at 10:55 AM on January 31

here we go: a large-displacement engine under low load (such as at highway speed) is less efficient than a small one under higher load (but totally not for the resons i expected). this is the rationale behind variable-displacement engines.
posted by klanawa at 11:03 AM on January 31

gjc: 2- $1500 will cost you $25 a month if you take a 5 year loan.

Only if the OP is able to get a 0% loan.
posted by Doofus Magoo at 2:04 PM on January 31 [1 favorite]

Ten years ago I had this choice. I ended up getting a 1999 Chevy Malibu with the smaller 4 cylinder 2.4L instead of the 6 cylinder 3.1L.

I was able to drive adequately fast in it, and it is the only car I've ever gotten a speeding ticket in (at about 6 months of ownership).

I get about 32 mpg, but the EPA highway number for the smaller engine is 30. The EPA highway number for the larger engine was 29. Assuming only1 mpg difference, over the past 10 years I've saved about 125 gallons of gas. At $2.00 a gallon that is $250 in savings.

The cost of the upgrade at the time I believe was $1,250. Today if I were to sell the car my the smaller engine is worth about $265 less. So, basically the reduced value of the car would about equal the gas I've saved. That means that we can take the extra cost as just that, it is an extra.

This supports the advice above. Consider the $1,500, make an assumption of how long you'll keep the car, and you can figure out how much you are paying each time you drive for that extra enjoyment of a little acceleration. I can understand how it might be worth $1 a day to some folks. For me the smaller engine has done everything I want and by saving that money we were able to 'splurge' on more accessories for a 2002 MINI Cooper a few years later.
posted by meinvt at 4:41 PM on January 31

As others have said up-thread, if it's a ford hatchback that costs 20 grand, probably not worth the extra few spondulicks; if it's an Electric Blue Maserati it most certainly is.
posted by Nick Verstayne at 5:12 PM on January 31

Seconding that the big engine is unlikely to save you much time, and that the resale value will likely be higher.
posted by box at 5:33 PM on January 31

Unless you need to tow a trailer, the sole reason to get a bigger engine is "fun."
posted by zippy at 1:42 AM on February 1

This is a somewhat philosophical question, especially w/o any details. We don't even know where you are, for that matter. (Most American cars are overpowered these days.) I will assume that you're not talking about a sports car.

Yes, more power is always fun. It can also be more expensive to fuel, insure, maintain and repair. And I don't buy the "saves time" argument.

When I bought my first new car, I had a choice of two engines ... and I had employees of that automaker (not dealerships) tell me not to waste my money on the bigger engine. Studying the specs confirmed this advice; the slightly bigger engine actually had less torque.

On the other hand, I could describe a current vehicle where the difference in power is dramatic, yet the difference in fuel economy is all of one mile per gallon. Unless the insurance costs were higher, I'd probably go for the upgrade in that case.

My point is that there's no one right answer, and without some specific information, this can only be a philosophical question.

I will suggest this: Reframe the question to "does the standard engine provide enough power"? If the standard engine feels lacking, to the point where it's not fun or potentially unsafe because it's too wimpy to get you out of trouble when you need it, that's a compelling logical argument for upgrading. Otherwise, save your money.
posted by pmurray63 at 1:45 AM on February 1

A more powerful engine may be more fuel efficient than a small one if the result is that it doesn't have to work as hard.

i'd like to see some (non-anecdotal) evidence for this.

Top Gear showed that a Toyota Prius can get worse MPG than a BMW M3. Conclusion, "it isn't what you drive, it's how you drive it".
posted by JonB at 3:06 AM on February 1

Yes, you're missing most of the reasons.

Why don't you find an online forum for the specific car model and post your question there? That way, people who own the car can express their regrets or recommendations from experience with that particular car.
posted by luckypozzo at 11:02 AM on February 1

Top Gear showed that a Toyota Prius can get worse MPG than a BMW M3. Conclusion, "it isn't what you drive, it's how you drive it".

is this meant as a rebuttal? (kidding).

i can make my tacoma get worse mileage than a 747. i'll just leave it idling for the next six months.
posted by klanawa at 7:10 PM on February 3

Eh, didn't you watch the clip? The prius and the m3 drove the same speed around the track. The m3 got better mileage as its bigger engine was still more efficient than the prius at that speed. For that particular fast style of driving, the more powerful engine was more fuel efficient as it didn't have to work as hard as the prius which was at 100%.
posted by JonB at 10:53 PM on February 3