Mustang 3.7

[Spazdog]

I drove 3.7 auto Mustang and I was a little disappointed.

By my highly calibrated butt-dyno calculations, my PT Cruiser pulls harder at 2000 rpm than the Mustang did. A lot harder. Earlier 4.0 Mustangs pulled better. My Mazda pulls that hard and it's about to turn 140,000 miles with a 700cc displacement deficit.

I realize that the automatic is programmed to maximize fuel economy but in manual mode in second gear at 2000 rpm, I really expected it to accelerate better. I won't be buying an automatic. I hate that chintzy little rocker switch on the side of the gear selector. It's kind of in an unnatural position and if you are going to take your hand off the wheel, you might as well move something. fore to aft like my Mazda or side to side like my Chrysler. Should have put paddles on it or stuck the +/- buttons on the steering wheel like Porsche was doing.

I still can't get over how sluggish it felt. I kept thinking that I liked the German SOHC 4.0 Ranger/Exploder mill that preceded it better. I know that the Cologne 4.0 will fall on it's face at the rpm that the 3.7 is hitting it's stride but it seemed easier coming out of a corner on the power in the old engine.

Does the 3.31 ratio Performance package make that much of a difference over the two 2.73 Mustangs I drove? If so there may be hope for a nice spot in the garage for a Mustang afterall.

 

[bdcardinal]

Yes that rear end ratio will help dramatically. If you think the 3.7 and 4.0 were powerful, don't drive a new 5.0.

 

[mechanicx]

I think the 3.31 gears would make a lot of difference. That's one thing about the old pushrod Camaro/Firebird/Mustang V8 motors. They didn't even make as much peak HP as the late model 3.7, but they made tons of low and midrange torque and it helped their automatics stayed in a lower gear and were quick to downshift. Plus there's no built in throttle lag. so they felt very snappy when cruising.

Although, I always thought the 3.7 Mustang felt pretty snappy. If you put it in sport mode and gave it a lot of throttle, they seem to move out good.

 

[NateDN10]

I drove a rental 3.7 Mustang last summer and I'd have to agree - compared to the two decidedly non-sport cars we have, I had expected the Mustang to feel significantly faster, even in V6 form. But it didn't.

 

[Nick R]

More horsepower, but the torque is at a much higher RPM than older engines. This applies to most all engines. The old 4.0L mustang motor just has more low end grunt than the modern V6 does. You put your foot down and it goes, but it's not available at the low RPMS people are used to.

 

[umungus1122]

Originally Posted By: Nick R
More horsepower, but the torque is at a much higher RPM than older engines. This applies to most all engines. The old 4.0L mustang motor just has more low end grunt than the modern V6 does. You put your foot down and it goes, but it's not available at the low RPMS people are used to.


Exactly. Today's common place cammer engines need to rev to make power. Throttle manipulation needs to be different on OHV engines with the torque down low. In daily driving with my 305 I almost never exceed 2k rpms, usually 1200-1500. Gentle on the pedal and the torque will move you along.

I bet that 3.31 ratio mustang would be a lot snappier than a 2.73. That's a fuel economy ratio. Better yet, swap in some lower gearing.

 

[aquariuscsm]

My gf has an 07 4.0 Mustang and it has way more power and sounds good and throaty. The new 3.7 Mustangs just feel really weak and flimsy. On paper they're supposed to have alot of power,but driving one it's definitely not there. The old 4.0's blow them away!

 

[SteveSRT8]

Never trust the butt dyno. It is notoriously inaccurate!

 

[rationull]

I had the same experience. I've driven a base 2.73 ratio 2011 V6 and a 3.31 with manual transmission. I don't even remember whether the 2.73 I drove was a manual or auto, which should hint at how I felt about the car. I think it was a manual though.

The 3.31 *did* feel better, but it still didn't feel that great. As Nick pointed out, the torque peak is relatively high, the engine is a little bit of a revver, and the car is not really a lightweight. If you look at the numbers, the car is relatively quick, but it did NOT feel quick in my test drives.

It doesn't surprise me that you thought your PT felt stronger. I test drove the V6 Mustang around the same time as I test drove the WRX (which I ended up buying) and the WRX feels MUCH stronger when boost comes on, although if you look at the 5-60 MPH acceleration numbers (not 0-60 where the AWD launch inflates the performance) the Mustang actually has the edge I think (higher redline and more power). Talking about the 3.31 axle ratio Mustang here though.

TBH my impression after drive the V6 (BOTH of them, but especially the 2.73) is that they didn't really "feel" appreciably faster in an onramp pull than my wife's Mazda3 2.3 (not turbo). I know it *is* faster, and it's RWD, but it didn't have any kick. I think I've posted this before, now that I'm re-reading what I've typed.

It's a reasonably quick car though -- it just depends on what you're comparing against. My advice would be not to test drive the V8 unless you want to spend the extra money though, because it's in a different category and is awesome.

 

[Stanley Rockafeller]

Originally Posted By: SteveSRT8
Never trust the butt dyno. It is notoriously inaccurate!


+1

I had one in SoCal recently and loved it! It also was auto with the 3.7.

And yes, changing the gearing from the 2.73 to 3.3 will make a huge difference! I just loved the car for it's power and overall fuel economy compared to my dd

 

[tenderloin]

2010 Mustang 4.0

VEHICLE TYPE: front-engine, rear-wheel-drive, 5-passenger, 2-door coupe
PRICE AS TESTED: $25,540 (base price: $21,845)
ENGINE TYPE: SOHC 12-valve V-6, iron block and aluminum heads, port fuel injection
Displacement: 245 cu in, 4009cc
Power: 210 bhp @ 5300 rpm
Torque: 240 lb-ft @ 3500 rpm
TRANSMISSION: 5-speed manual
DIMENSIONS:
Wheelbase: 107.1 in
Length: 188.1 in
Width: 73.9 in Height: 55.6 in
Curb weight: 3421 lb
C/D TEST RESULTS:
Zero to 60 mph: 6.6 sec
Zero to 100 mph: 17.7 sec
Street start, 5–60 mph: 7.3 sec
Standing ¼-mile: 15.3 sec @ 93 mph
Top speed (governor limited): 114 mph
Braking, 70–0 mph: 182 ft
Roadholding, 300-ft-dia skidpad: 0.85 g
FUEL ECONOMY:
EPA city/highway driving: 18/26 mpg
C/D observed: 19 mpg

2013 Mustang 3.7
VEHICLE TYPE: front-engine, rear-wheel-drive, 4-passenger, 2-door coupe
PRICE AS TESTED: $32,655 (base price: $26,995)
ENGINE TYPE: DOHC 24-valve V-6, aluminum block and heads, port fuel injection
Displacement: 227 cu in, 3726 cc
Power: 305 hp @ 6500 rpm
Torque: 280 lb-ft @ 4250 rpm
TRANSMISSION: 6-speed manual
DIMENSIONS:
Wheelbase: 107.1 in
Length: 188.5 in
Width: 73.9 in Height: 55.8 in
Curb weight: 3530 lb
C/D TEST RESULTS:
Zero to 60 mph: 5.2 sec
Zero to 100 mph: 13.4 sec
Rolling start, 5–60 mph: 6.0 sec
Top gear, 30–50 mph: 16.1 sec
Top gear, 50–70 mph: 14.9 sec
Standing ¼-mile: 13.9 sec @ 102 mph
Top speed (governor limited): 112 mph
Braking, 70–0 mph: 164 ft
Roadholding, 300-ft-dia skidpad: 0.91 g

FUEL ECONOMY:
EPA city/highway driving: 19/29 mpg
C/D observed: 21 mpg

 

[SteveSRT8]

^^^Thanks, tenderloin. Proves my point perfectly.

My FIL has a super dark red convertible 3.7 Stang and for a V6 it is a spunky little performer!

 

[aquariuscsm]

The 4.0 is an iron block? I'm even more impressed!

 

[jimbrewer]

Can't imagine anyone thinking this isn't one powerful engine....Its performance does improve considerably after break in, about 4K of city driving for me.

 

[SwampDweller]

It is funny how different people see the same thing differently. After 16,000mi on wife's Mustang, I can tell you it will blow away older vintage V8's and is very happy pulling to 6500-7000. On highway trips at 70mph it returns 32mpg(done it many times, hand calculated)

Was impressed enough with the engine after driving for 6 months, I bought an F150 with this engine. I put 18,000mi so far on the truck, so far, so good. Would recommend.

 

[mechanicx]

The only think I can figure is they are expecting a lot of part throttle snap. That's not how late models operate now. You have to step into the gas pedal and then they will go like a bullet.

 

[Spazdog]

Originally Posted By: bdcardinal
Yes that rear end ratio will help dramatically. If you think the 3.7 and 4.0 were powerful, don't drive a new 5.0.


I know....I also know I would hate myself everytime I filled it up and everytime I paid my insurance premium if I indulged in my desire for the 5.0.

It's not so much that the Cologne 4.0 felt powerful, it was just feels more responsive at all the rpm levels that it makes power at.

Originally Posted By: SteveSRT8
Never trust the butt dyno. It is notoriously inaccurate!

Terribly inaccurate.
But it is the primary input for the fun-meter which is why you buy a car like a Mustang instead of something practical but boring like a Scion xD.

Originally Posted By: mechanicx
The only think I can figure is they are expecting a lot of part throttle snap. That's not how late models operate now. You have to step into the gas pedal and then they will go like a bullet.

That's probably a lot of it. The throttle did feel eerily similar to my Mazda.

Again, I'm absolutely certain the 3.7 will kill, gut and devour the 4.0. I just liked the way the 4.0 responded better. The 4.0 is done by 5500 rpm and the 3.7 is hard into the fat part of it's powerband then.

 

[cptbarkey]

the 4.0 is best left to rot in the farm tractor where it belongs. the 3.7 is a very respectable engine and given the opportunity/need i would not hesitate owning one in truck or mustang form.

 

[SteveSRT8]

Originally Posted By: mechanicx
The only think I can figure is they are expecting a lot of part throttle snap. That's not how late models operate now. You have to step into the gas pedal and then they will go like a bullet.


Throttle tip in is huge variable, sometimes they just get it wrong. It's likely addressable in an aftermarket tune since it's a DBW engine.

 

[GMBoy]

Originally Posted By: cptbarkey
the 4.0 is best left to rot in the farm tractor where it belongs. the 3.7 is a very respectable engine and given the opportunity/need i would not hesitate owning one in truck or mustang form.




This topic sounds exactly like when Jeep dropped the 4.0L I6 for the 3.7 V6. Mountains of torque vs high revving horsepower. I choose the farm tractor motor.