# Acceleration Pick-up

I’ll be buying a new sedan with a 4 OR 6 cylinder engine.

I would prefer to have some sense of “pick-up” when needed, say from a stoplight or to pass.

New car specs often talk of horsepower and torque. Is there a website or math method or other rule of thumb to determine acceleration, i.e. “pick-up”?

Thanks,
SG

Auto reviews from Motor Trend, Car & Driver, etc. normally publish a car’s times 0-30 mph and 0-60 mph.

Rule of thumb would be horsepower/weight ratio and torque/weight ratio. Can be somewhat mitigated by transmission choice or final drive ratios.

New car specs often talk of horsepower and torque. Is there a website or math method or other rule of thumb to determine acceleration, i.e. “pick-up”?

NO…You can find out what the hp or torque of a vehicles engine is…but but that doesn’t necessarily relate directly to how well it’ll accelerate. The only real way to tell is to test drive them.

I agree with Mike. You would need to drive the vehicle and make it the V6. The odds of better acceleration is increased with a larger engine in most cases.

Here’s a quick rule of thumb that isn’t perfect but makes the basic research much easier. Find out how many valves per cylinder the car has. You want 4 valves per. So in terms of “pep” a 4 cylinder / 16 valve engine is a whole different animal from a 4 cyl / 8 valve engine. The same with a 6/12 vs a 6/24. If you see things like SOHC (single overhead cam) or DOHC, (dual overhead cam), you go with DOHC.

This is far from perfect - but as I said, quick rule of thumb. The real “research” comes when you sit behind the wheel and test drive as MikeinNH said.

If you do want to get into comparing based on HP/torque, go by torque moreso than HP.

Yes, comparing published acceleration figures will be very informative for the OP.
However, there is no substitute for test-driving a vehicle and comparing all of the possible engines in that model for performance.

And, you shouldn’t take anyone else’s word for how well a particular vehicle accelerates.
If someone tells you that a particular vehicle has “adequate” power, that is a value judgement on his/her part, and you might feel that the available power is not really adequate.

As just one example of how people can be fooled, a car that accelerates with a lot of engine noise will be perceived as more powerful by most people, as compared to a vehicle with a lot of sound-proofing. Only a few test drives will truly give the OP the direct knowledge that he needs.

Great point–most people do mistake noise for power.

Test driving is the only way you can find out what you’ll like. Forget the data. Find something with a good reliability record that leaves you with a smile on your face.

If you do enough reading in magazines like Top Gear, Octane, Road & Track, Motor Trend, etc., one thing you’ll eventulaly realize is that acceleration can be measured and compared but faster doesn;t mean more fun, or even more drivable. Lamborghinis are known to be brutally fast, but ergonomically horrible and almost impossible for the average person to drive. Ferrarri Enzos have the same reputation.

And with a 4 or 6 cylinder sedan, the tranny ratios, number of gears, vehicle weight, and even the rolling stock become a big factor in how well the vehicle accelerates. Realize too that horsepower and torque work in curves. An engine with max horsepower of 160 but a torque curve that keeps it accelerating throughout the RPM range cane accelerate much better than an engine with 200 hprsepower but a sag in the middle of the range and two fewer transmission gears.

Get a Consumer Reports New Car Preview ate th local bookstore, pick out soms that look interesting to you, and plan a weekend or two doing test drives.

mleich wrote:
Auto reviews from Motor Trend, Car & Driver, etc. normally publish a car’s times 0-30 mph and 0-60 mph.

I think the passing time (like 30-to-50) published in some magazines gives a more realistic view of how fast a car is in real-world conditions.

Standing start times give you a good idea how well the car will accelerate from a stop light, and for some highway entrance ramps. The 30 to 50 times can also provide information about merging as well as passing on the highway. They all go together, as some cars will have good standing start times buy exhibit anemic passing. You can use all those times in the car mag tests and the driver impressions to create a short list to test drive.

Acceleration isn’t just power and torque, but the power to weight ratio of the vehicle. Then there is gearing and how well the transmission responds with downshifts, etc. etc. As you read car reviews look for comments like “lively”, “quick”, “responsive”, and “eager to pass”. In most models that have a 4 and 6 cylinder option, the 6 would be the quicker of the two.

Looking at statistics help, but some cars just feel lighter, quicker, and more agile than others. Some 4 cylinder cars are plenty of fun to drive.

Great answers, thanks to each of you!

I’ve already started acting on some of the recommendations such as reading Motor Trend and other test drive reviews.

But the overall consensus seems to be: test drive the vehicle.

I think that when I narrow down my choices, I’ll have my numbers and reviews in mind, but will definitely use the test drive to confirm that the engine responds and feels the way the numbers and reviews imply.

Thanks everyone!
SG

you want a quick ,fairly economical V-6,try a Mustang or Camaro-Kevin

Are you looking for the FASTEST car in your price range…or one that’s FAST ENOUGH???

Recent cars are MUCH faster than cars of only 15 years ago, so if you’re coming out of an older car you will be surprised at the power and economy of many 4 cylinder cars these days. Makers are eliminating v6 engines from mid size cars, the ‘base’ 4 is plenty good enough for most, and a turbo-4 is available for that last 10% of folks ‘needing’ more power.

Also, the 4s are bigger now, often 2.5 l, close to the 3.0 l v6s of years past, with similar hp (around 200 for some).

There is more to acceleration than just power…The weight of the vehicle is VERY important too…Also, today, with multi-speed transmissions and greatly improved torque converters, all computer controlled, can multiply torque and produce VERY lively acceleration up to 60 or 70 mph…At that point you run out of gearing and it takes brute horsepower to maintain high rates of acceleration…It should also be noted that high rates of acceleration require large amounts of energy…

“Recent cars are MUCH faster than cars of only 15 years ago, so if you’re coming out of an older car you will be surprised at the power and economy of many 4 cylinder cars these days.”

Yup!
There was an episode of Top Gear (UK version) a couple of years ago, where they compared the fastest cars of the '60s–an Aston Martin DB-? and a Jaguar XK-E–with cheap, modern, 4-cylinder econoboxes.
In almost every case, the modern econoboxes out-accelerated, out-handled, and out-braked the extremely expensive performance cars of the '60s. (And, of course, those cheap little modern cars also had superior crash protection for their passengers.)

The contrast with more recent cars would be similar, i.e.–what appears to be a cheap little 4-cylinder car may actually outperform a luxury/performance car from 15 years ago.

Power is meaningless if you can’t put it on the road

I couldn’t find the clip, but I believe that was the car they used in a tug-of-war challenge against an Olmpic tug-of-war team. Sadly, the car lost because it just couldn’t get the power on the ground

Weight of the car is probably just as important as ANY horsepower rating. You can quickly change a peppy compact into a dog by loading it with friends and party favors. So, overpowering cars and trucks today is done to give acceptable performance when loaded. Using that logic, a Corvette should be able to handle a pretty big passenger.