Gas Mileage Discussion: Mazda Engine Efficiency *LONG*
 

This isn't a regular gas mileage discussion thread, I've seen quite a few of them already pass by. What I'm wondering is first of all, what kind of mileage people are averaging. Then with that, I'd like to compare it to other car manufacters.

For example. My mom has a 2002 Saturn SL2. Yea yea, you guys don't like Saturn's, big deal. It's a commuter car, whaddaya want? :)

Anyway, the specs on a 2002 Saturn and 2002 Protege are pretty close. (S) 1.9l to (M) 2.0l, (S) 124hp to (M) 130hp, (S) 122tq to (M) 135tq.... (S) 24xx lbs to (M) 26xx lbs... Pretty closely matched cars. (All info taken from Edmunds.com)

Going on that, I'd also like to compare my '90 protege with my sisters '93 Saturn SL2. Again, very similar cars. (S) 124hp, (M) 125hp, (S) 122tq, (M) 114tq. The weight it within 50lbs of each other as well. Also I'd like to point out that my sister's car is automatic.

So, with that information... My sister's car, drivingly the same style, areas, and distances, get's much better gas mileage even with the automatic transmission. I get usually around 24-26mpg in the protege with mixed driving (which is normal from what I've read on here), and my sister has yet to get under 30mpg. My mom just took it on a trip out to Pittsburg and back, a little over 180 miles each way, and she said she got about 37-38 mpg. My mom isn't a granny driver, she drives just like I do when I'm driving 'normal'.

Hell, I've yet to get that sort of mileage with my 323 which is hundreds of lbs less, smaller engine, less HP, etc. etc.

My moms 2002 (she was driving the '93 because she got in an accident with her 2002, it was getting body repair done) get's around 33mpg normal driving (back and forth to work, to the store, etc.) and she's actually hit about 40mpg flat on a longer trip.

Not only this, but I'd say that the performance between the comparable cars are quite close. Obviously I should be able to take my sisters car because it's an auto, while I'm manual... But manual for manual, it would be a close race, even with the newer cars.

I know there are a ton of factors mixed into how good of gas mileage you can expect (gearing, driving style, aerodynamics, aside from the normal factors), but can I assume mazda's engines are less efficient than some other company's? What's everyone's thoughts on this situation? Sorry for the long post

Yeah, i'm averagng about 25-27 MPG with mixed driving on my 03 p5. Hearing that your mom got 40 MPG is pretty freaking crazy. I'm thining something along the lines of that car's gearing allows for low RPM, high speed driving, unline P5, which is going like 4k at 80 mph....
My last car, 01 Celica GT-S, averaged about 25-27 mpg too, but it had a 1.8L and the car was 2500 lbs. I did have it slightly modded and that mileage includes a LOT of aggressive driving. I think the best i ever got was like 29 mpg or soemhign, and that car has a 6th gear too :P

2.0L 5spd (P5)

as of my last entries into the spread sheet:

15,495miles total, 27.3MPG (US gallons) average mixed over highway and city

I think it's gearing...my dad's 1990 Cavalier with 2.2. l and 5 speed used to take 6 liter/100km on hwy(vs Protege's 7-8)
I don't think that 2.2 Cavalier is more efficient than Pro(it was with TBI and technology wasn't up to Mazda in 2002 for sure-but sure it was geared differently.
Alex

I think you guys might be right... I'm taching at 3k just going 60 mph in my pro... That's nothing less than ridiculous... I'll have to see what my mom's car does at those RPMs when she gets it back.

2001 2.0 pro ES, mixed driving: 29-32 mpg (my car)

1999 1.6 civic lx, mixed driving: 32-36 mpg (wife's car)

How do you get those fuel economy numbers, the MAN?

Well, it can't hurt that he's in a warm/hot area. The warmer the air, the less dense it is, therefore the less fuel is mixed with it.

1986 Chevy Celebrity (bought used), auto, 6cy, 89 octane gas, college car, stock: 27-30 mpg

1993 Pontiac Grand Am (bought used), auto, 4cy, 89 octane gas, mixed city and highway, stock: 29-35 mpg


1997 Ponitac Sunfire (bought new), auto, 2.2L 4cy, 89 octane gas, mixed city and highway, stock: 33-35 mpg.


2003 Mazda Protege ES (bought new), auto, 2.0L 4cy, 89 octane gas, mixed city and highway, stock (see sig): 24-26 mpg.


That's what I remember. My first two cars were used beaters that I haven't had in years.

And don't forget the tornado!!!! :D

So anyways, does anyone have any theories besides gearing that would be robbing us of mpg? I rememberd back to my '89 Beretta GT 2.8l V6, I used to get 24-28 with that beastie, and it's a *gasp* GM product.

Heh heh, like it really makes any difference!

I was told by a Toyota dealer that the engines on Saturns run a lot warmer and therefore get better mileage. (What does a toyata dealer know about saturns?? ) "I don't know" But that was his theary! He also said that the saturns might not last as long overall, compared to our cars! We also have dual cooling fans and so do neons and they also get crappy as hell gas mileage!

Could be... But my sisters car has roughly the same mileage as my pro (150,xxx) and it runs just as good. I was really impressed because her tranny has no 'clunk' to it that eventually happens to all automatic trannies. It must have been replaced before she got the car.

My mom has been buying new saturns since '97, and I don't we've had a maintence issue once. There was a recall for some seatbelt thing in '00, but that's all I remember.

I would think the dual cooling fans wouldn't matter, because it's pretty much the temperature (i.e. volume) of the air coming into the engine that would make a difference in gas mileage. Who knows? It's a good subject none the less :nod:

What’s the problem with your understanding about the car you bought?
 

Designing a car and selling it to meet the needs of varied locations and people that drive them has always been a problem. Some car companies take the tact; “since the federal government (US), dictates that a car company as a whole must meet a minimum MPG” the design of small cars and their gas mileage will offset the large cars and their lack of it. None, or very little consideration is given to performance, or how it will ride, or if it is fun to drive.

That said, I have been reading several posts about the Mazda’s “high revving” and low gas mileage. To this I would like to say “Mazda did not have to worry about “corporate MPG”. They don’t build cars that weight 2 tons and seat six people or SUV that are 30 feet long and need to tow 8,000 pounds. They build small light weight cars to meet the needs perceived by their marketing research. They can build "fun".

Mazda has elected to build cars that are fun to drive while still meeting the market they are in, thus 4 doors are a must (except sport car). The second consideration was most of these cars will be sold to young singles, or newly married couples with small children and putting a baby seats in the back seat and strollers in the trunk mandates 4 doors and large trunks. The engineers needed to make the cars comfortable for 4 adults (US size) to be able to market their car in the US (biggest market area they have), so they set out to make a fun to drive 4 door sedan that will cruse at highway speeds and idle in stop and go traffic without most people complaining about engine vibration or continually shifting gears while at highway speeds when fully loaded going up hills. They did not have to take in to consideration fuel economy since it burns 89 octane and gets pretty good mileage on that. I personally feel they did a good job of that.

Ever ridden in a sunbird on the highway and come to a overpass and the transmission shift down to get the car over the top? Does your Mazda do that? The RPM are high to get the engine in a power bandwidth that will allow it to cruise at 60 – 80 without have to hunt for a gear to maintain speed with a load. They put the 2.oL in this year so that they would have more low end pick up so that accelerating on to a entrance ramp will not be a toss of the dice. In short, the engineers designed and built a car that will appeal to their market while keeping the “fun” in it (Zoom Zoom). The Mazda corners better, has less roil, and better pickup of any car in it’s class (money). It is comfortable to ride in around town and in a pinch you can put 4 full size adults in the car with luggage and go on a trip without having to allow extra time to get to the destination because you know that you are going to have to cross a mountain.

This car was never designed to be a “mass people mover”. It was designed in mind that most of the time it will have no more that 2 people in it with no luggage, moving around town in stop and go traffic. They made that fun. They made that easy on the engine and transmission. They made that with style.

Enjoy the car for what it is. It is not a world class race car, It is not a SUV that can pull a 40 foot boat, it does not wallow around town and drinks gas like there is no tomorrow. It is a wonderful car for the money and should last a long time with minimal cost for repairs, if you treat it well. To some of you that are just starting out I say "good choice" be glad you don’t have high insurance premiums, repair cost, and high gas bills. To those of us that are later in life I say “good choice” you have decided that transportation is just that. It is an expense and you should keep it low while feeling good about what you drive.

Bob

man you guys, i get sooo happy when i hit at least 23mpg. I average 21-22. I dont drive agressivly. I got an AT. The highest ill rev is like 5 and thats NOT often at all. I do a bunch of city driving though, and some very very slight (not steep) hill driving. I wouldnt even put in the hill part but thats the only thing i can see why my mpg is so low. I dont carry a lot in my car so its like the stock weight. The only thing a carry are books for school, and thats about it. I still like the milage i get though, im just dissapoited cuz i want to be seeing the 25-27 everyone else is seeing. . .

EDIT: i forgot to metion, I am on 18 inch rims on 35 series tires. Before the rims i was pulling like 22mpg consistantly. Havent recently watched it with the intake and the wheels. If i got bigger wheels, then technically, shouldnt i be getting more mpg?

Not really. The overall diameter of the tire should be close to what the 16" rims had slapped on them.... maybe 55 series tires? I dunno. In anycase, it should be very close therefore no difference in MPG in terms of tire diameter. You may in fact be getting worse mileage now because those 18s have to be heavier than the stock wheels. Heavier = more effort to move them = more gas used. The difference shouldn't be more than 1-3 mpg though.

It really is all a matter of gearing. My last car, a 4-cyl '98 Accord was geared the same as in 4th gear as my Protege was in 5th. Consequently, it actually got better highway mileage (about 30-32 mpg @ 75mph vs 28-30 mpg for the Protege) than the Protege. Back when the the speed limits were 55mph, the Protege was still geared too short, and I got about 30-32mpg on the highway. My friend with a '90 LX auto reported getting close to 40mpg at a steady 55mph, taching about 2000rpm.

But, most 4-cylinders won't hit their top speed in 5th gear, like Proteges do. I for one have always wished for a much taller 5th gear. Spinning 4k @ 80 mph is silly. There are very few freeway grades that I can't climb in 5th gear even when loaded (and at 10,000 feet).

But, driving around Yellowstone last year, I got 38 mpg, because I couldn't legally drive more than 45mph (and who's in a hurry in Yellowstone).

Ive compared different cars sometimes, with comparable engines and power, and some are a lot better on gas than others.

I think in the case of the MAzda, gearing is a factor, as they rev entirely to much while highway cruising. I would gladly downshift to pass or go up a hill and enjoy better mileage than drive around in 5th gear at 4000 RPM!

But for me, the Mazda is the slowest and least powerful car Ive ever owned (im 34 and I have had 11 different vehicles) so it is a dream on gas to me regardless....

Anyway, besides gearing, there are a lot of engineering differences in engines, and a lot of factors could determine gas mileage differences..

I think the exhaust manifold/1st cat has a lot to do with the low fuel economy/engine efficiency. When I installed the OBX header, there was significanly less engine braking when laying off the pedal. When cruising, less pedal was needed to maintain a speed. And yes, fuel economy did go up.

The gearing is probably the biggest problem though. The Saturn that we traded in for the P5 regularly hit 40mpg. On the freeway, the tach rarely passed the 2.5k mark. My Grand Prix GTP at 1/2 ton heavier than the P5, also managed 30+mpg on the freeway. The only time it passed 3k RPM was when making its low 13 sec 1/4 mile passes.

i do quite a few trips to and from california, so i have a good idea about this one.

i/h/e on my 2002.5 p5, going 80mph at 3500 rpms. i average right under 31mpg. on a day with not so much headwind coming into california, i can get up to 32mpg. on the way back, (going from basically 0 elevation to a little over 2000 feet), i get 30mpg. same speed. tire pressure's at 40psi on 205/40/17. engine specs are 130horse/135tq pulling about 2900 pounds with me in the car and my stuff.

now with my beater 96 civic ex, going 80mph at 3200 or 3300 rpms, i averaged 35mpg. i had a dirty as all hell stock air filter that was so black the filter element looked like it was black instead of the yellow it really was. the car is also in desperate need of an oil change and spark plug replacement. tire pressure was at 35psi on 185/65/14. engine specs are 127hp/106tq pulling 2600 pounds.

i'd get pretty much the same mileage on 6 gallons now in the civic as i did on 7 gallons in the p5. i've figured i'm now saving $10 (give or take a few dollars depending on gas prices) a trip on gas alone.

i'll let you guys know how the car does this weekend after it got a tuneup.


edit: i forgot to mention the p5 had 30K miles on it and the civic now sits pretty at 96K miles.

and as to the original question of mazda's engine... the fs-de has been in existence in some form since circa 1993 on the 626. i'm not sure about this, but before being put in the 626, there were renditions of the block in the mazda series trucks. hence, we don't get the crazy gas mileage from the newer economy motors from other makes.

i wonder if anyone will have better mileage in another 3 years?

That's true, but I don't think warmer air will decrease fuel consumption. Considering only temperature, HP is a function of the square root of the change in absolute temperature of the intake air. Assume an ambient intake air temperature of 59 deg F at cruise in closed loop. The density of the intake air as "read" by the MAF sensor will trigger an injector pulse duration that maintains the stoichiometric A/F ratio. Further assume a throttle opening X is required to produce enough HP to maintain a 65 MPH cruising speed.

Now assume an ambient intake air temperature of 77 deg F with the same conditions. The less dense intake air will therefore require less fuel be added to maintain stoich than in the first case. But at the same throttle opening X in this case, the HP output will be less. Therefore, in order to maintain the same 65 MPH cruising speed as in the first case, the throttle opening will have to be increased to X+ in order to provide the same HP. Thus, fuel consumption will rise again overcoming the effects of the less dense air.

IMO, the relatively poor fuel mileage of the Protege is due to its relatively low overall gear ratio (high numerical ratio) in 5th gear.

Does anyone make gears for the Protege yet? They do it for Domestic Muscle, why not us?

I dont know about that goldstar I got a record low milage of 16 mpg in the winter, now at least im in the 20's.
I would like to point out that Im really trying to get the milage up now. Full tune up and hyper ground goes in today maybe tomorow.

I would like to point out I have a 1.6l

I got 29.5 last two tanks in my '03 MSP.

30 ish 03 LX.

BTW, a stock 97 Saturn SL1 with a wieght reduction will take out a Miata. Ive seen it. Its Laughable. Dont doubt the saturns man...

SO WHAT if the damn thing is basically all plastic. I mean, I hear the frame is just blow molded plastic. Anyway.. i donno. Ive been up for 49 hours and had 3 pots of coffee in the last 20 mins. Ramble ramble :tit:

fuel mileage
 

98 protege 1.5 5spd 50 miles each way commute 1/2 75mph 1/2 60mph never less than 35 mpg ( once I'm on the highway I don't have to downshift for 50 miles)

fuel mileage aero
 

Have to think major factor in ambient temp v fuel mileage is air density/ increased drag

Holy Lazarus, Batman! Resurrected for the second time!

BTW, in case you didn't read the whole thread, 3rd gens get crappy MPG.
It's the price paid for a little extra low-end torque.