Pardon my ignorance: why is the 7M-GE so much less efficient?
 

The 3.0 V-6 in the '07 Honda Accord make 244 HP, 211 ft-lbs of torque and gets 21/30 MPG. The 3.0 7M-GE makes 200 HP, ~190 ft-lbs of torque and does about 18/23 MPG. I understand that the 7M has a longer crankshaft being a straight engine instead of a V but this doesn't seem to me to be enough of a difference to make such a disparity between the two.

Can someone shed some light on this for me?

(I'd like to point out that I am aware there is a roughly two decade difference in the technology of these engines. Were we just that much less knowledgable about what could be done with an engine in 1987? It just seems to me that given that the Porsche 959 came out around that time we (as people in general) couldn't be THAT primitive compared to today.)

You answered your own question. 17 years of difference between the two. And this really probably isnt the place to knock on a SUPRA ENGINE. Thats not even comparing apples to apples.

You wanna compare apples to apples, take a look at a 94 supra with a 2jz-ge.

Makes 220hp and its still 13 years older than ur honda engine. And an I6.

And again theres another honda making 30 less torque than it does hp. The torque of the 2jz-ge is even still more than the honda v6 13 years newer than the 2jz.

I think my point is proven.

I'm not knocking the Supra engine; just this evening I handed over a stack of $100 bills for a Supra and I am thrilled that I did. I've waited 18 years for this day. I'm just trying to understand a little about engine technology.

Maybe a good followup would be "why can't the 7M make numbers like that?" Let's compare apples to apples: the 2002 BMW straight 6 3 liter makes 225 HP and 214 ft-lbs of torque. The Honda is tuned to be a Honda; I imagine that even if I could put that engine in my Supra it wouldn't perform like my Supra does now. Could today's technology be applied to the 7M to make numbers like the 330i or is the block all wrong for what we now know?

BTW...the mpg numbers on the beemer are 19/27, much more in-line with the 7M. I expect that the 7M probably has a much broader power band than the Honda powerplant. No engine is both efficient and powerful otherwise they all would be.

This is a simple case of you being clueless.

Ya there's a good 15 year difference.
I have a 91. 200hp n/a.
With minor mods 250 is obtainable with no real work but if I were to buy a new block and build big. Do you think BMW would allow anything to leave a facility poorly tuned?? Apples to apples???????? toyota vs. bmw


Apples to Apples. The new version of the 08 supra, along side the same 350z.
I'm hearing there's going to be a small block v8 introduced and quite possibley called the 400z


Japs Don't think Like Jerries and we Don't think like either of them.

Play nice. ;)


Even if you were comparing one Toyota to another there are a lot of things not being taken into account here. Compression, volumetric efficiency, internal resistance and friction, interia and the weight of the stock internals, the RPM at which the power is made, the tradeoff between torque and HP, bore, stroke, valve timing, factory tuning, and so on.

cre is correct, its very difficult to make definate comparions about vehicles, engines, drivetrains, simply by numbers due to the fact that there are millions of things that you can adjust on cars these days.. the only way to really compare them is by driving.. you cannot compare simply by power the power they make.

comparing a 1987 supra to another car of its day of equal price range is very difficult because as much as we wish our cars were built as high-performance race cars.. they weren't. the mk3's were built as luxury cross-country GT (grand touring) cars. think about it, they came with power seats (who knows how many directions they're adjustable), power windows, automatic a/c, headlamp washers, adjustable suspension, adjustable steering wheel, and the car weighs in at over 3500 pounds. this is in no way being able to be compared to a high-performance vehicle such as a porsche.. truth be told is that the supra cannot be accuratly compared to any other car from its day. It is a very unique vehicle.. don't try and compare your numbers to anyone else because supra's are so tuneable and make so much power with few mods (assuming its turbo) that it's unheard of.. now idk about 250 horse with few mods on an N/A.. i just don't believe that but who knows.

I don't try to compare my Supra to anything else because it is very difficult to do so for all the reasons listed above.

I like this response better than being told I am just clueless. I started out by saying I don't know the answer to this, silly me for thinking that a forum frequented by people knowledgable about this car/engine (and engines in general) might be able to help me understand what makes this engine of 20 years ago different from the engines being made today. I thought comparing the BMW engine to the 7M was actually a good comparison since it makes sense that 20 years later the 3.0L straight 6 (a good design to start with) could be improved by about 10-12% in HP given a similar performance target.

I'm sorry dude...., but you did kind of come off as knocking on supras a bit.

And that may not bother anyone else. But personally, I was a bit offended.
Because you have or had no idea as to how much time and money alot of us put into these cars to keep them on the road.

You have to passionate about supras if you are to own one or it will never work out for you. These cars have a tendency to push back when they get tired of you pushing on them.

It read like you hadn't even driven one.

And you have to admit that comparing an 07 anything to any supra just isn't a logistical process.

Concider the 07 nissan z car to the 90 model z car. You just can't compare engines specs from that day and age to this one.

I'm tired of feeling like someones always banging on my ride.

Alot of these guys have a bit more tact than me. I shoot from the hip.
Tact goes out the window completely when you compare a supra to a honda.

You aren't far off. I had never actually driven one before I got this one 3 days ago. So far I have 302 miles behind the wheel but it's the best 302 miles I've ever driven. Don't worry about my passion. From a big picture standpoint there is not another car in existence I would rather drive than this, except a Mk IV, and maybe not even then because I don't know what kind of back seat room a Mk IV has. Yes, there are better cars but every one of them introduces some very undesirable factors. From a cost-performance-reliability standpoint nothing touches the Supra.

I asked the question wrong but I wasn't knocking the Supra; I was trying to learn what makes today's engines better so I could approach my Mk III with those factors in mind with an eye toward improving it.

Alright man. My Bad.

I feel alot better about that now that I know where you are coming from.

Alluminum. That's the biggest visible difference in engines of 07 to even just as late as the 90's. Everything on the new LS2 is alluminum. Everything on the z is the same. Hell the titan and tundra engines are all alluminum based engines.

It's much lighter than the steel that was used from circa 1980.

Well, I for one understand that your just asking a simple question and your not trying to bash a Supra... I gonna give my 2 cents and I dont even own one...

20 years of development in engine technology has to play a big part in this... Compare a ECU from 1987 to 2007, theres more brains in 2 chips from an 07 one to the whole Supra ECU... Inector sizes will play a role in MPG, compression ratio will, engine internals will, timing will, gearing will, vehicle weight will etc... Lots of things to look at.

Just for the record, I have a 1971 Datsun 240Z, 2.4L I6 SOHC with twin 46mm side draft SU carbs, a 4 speed (no overdrive), 3.54 gears, and it gets 24mpg highway... the car only weighs 2300lbs, but it just goes to show anything can affect MPG.

if you are unhappy with the efficiency of the M series engines, you can swap it out for the JZ series and keep the heart and spirit of a supra

congrats on your car. hope you have a thick wallet but assuming that you waited 18yrs for one means you dont have much green to coush your tootch (haha that rhymed). dont mean to discourage you. the majority of the people here are in that same boat and love their supras to death, its just with 20 yr old cars parts tend to go bad and you will get frustrated about that. anyways welcome to the supra brotherhood.

I actually have a decent amount of money to spend. The reason I haven't gotten one before now is that we have two kids and I have been supporting the family on just my income so the idea of getting a less efficient/practical car has been something the wife wouldn't exactly support. She has gone back to work and I got a job that is going to require that I drive about an hour each way everyday. Since the alternative is that we move (and she REALLY does not want to move) I finally put my foot down and said "I took this job which pays more than I have ever made to support us and if I am going to be driving 2.5-3 hours a day I AM going to have a car I enjoy driving." She realized that I was right and supported me actively looking for a Supra. I probably could have bought a Mk IV but the Mk IV would have been less practical when it came to putting 2 carseats in the back. I expect to put several thousand into the car in the next few years making it "new" again. A complete repaint in in the works but that will be the last thing I do after getting all the mechanicals taken care of.

the MKIV would also been more for insurance since they're worth quite a bit more than MK3's.. but the supra was a good choice for a highway driver going to work and such.. they're excellent cruisers and in fact are efficient on the highway.. i get about 22-24 on the highway and only 15-18 in the city. so good choice

putting the foot down ftw!

well you answered your question.. look at 1987 honda civic and how much power thaqt puts out. besides the super was designed to have potential. just like the 5.4 mustang has a hp potential of like 1500 whp...

i bet you the new supras have like an easy 450hp when/if they come out in '08

I'm hearing 400hp on the new ones.

its gonna be a v-6 standard optional v-8 i read

so maybe we're both right its gonna be the 5.7L that is in the tundra's with a stroker mod and some other bs

SUPA FAST

I just found out around a week ago that nissan is working on a 5.7 liter to be put into the z.


We definitley may be on the right track.

my hopes of a new supra have been shattered. i doubt they will actually come out with an actual supra. i think it will be another super car. but enough of this 08 supra talk/thread hijack, theres another forum for that...