questions about gas mileage among swapped motors

[1991corolla]

I have a '91 corolla (Katie) with 330,000 miles on it, still running pretty decent... she has the 4AFE in her and 3spd auto with o/d (pops in at about 48mph), and i get really good gas mileage, usually 30mpg or above... when i do a lot of highway, i even get as high as 35 (at 70mph)... haven't done straight highway yet on a whole 10 gallons, but someday i will...

anyways, to the point. i wanna get another motor for it, but don't wanna mess up the gas mileage, so i am thinking of going for another 4AFE. I was thinking of the 20v 4AGE for another corolla later next year, or maybe the GZE supercharged because of the higher HP.

What would be the gas mileage if i put the 20v or the GZE in the corolla i have now? i wanna get at least upper 20's to low 30's average gas mileage if possible... what's the best thing to do as far as an engine swap?

[SCT]

I think all 4Axx motors are roughly in the mid-20s.

[eage8]

Originally Posted by 1991corolla

I have a '91 corolla (Katie) with 330,000 miles on it, still running pretty decent... she has the 4AFE in her and 3spd auto with o/d (pops in at about 48mph), and i get really good gas mileage, usually 30mpg or above... when i do a lot of highway, i even get as high as 35 (at 70mph)... haven't done straight highway yet on a whole 10 gallons, but someday i will...

anyways, to the point. i wanna get another motor for it, but don't wanna mess up the gas mileage, so i am thinking of going for another 4AFE. I was thinking of the 20v 4AGE for another corolla later next year, or maybe the GZE supercharged because of the higher HP.

What would be the gas mileage if i put the 20v or the GZE in the corolla i have now? i wanna get at least upper 20's to low 30's average gas mileage if possible... what's the best thing to do as far as an engine swap?

35 is about right for a 4AFE. I'm actually surprised your not getting higher. it's probably due to the automatic transmission

a 20V 4age will get in the upper 20s easily. I'm getting about 23mpg with mine right now, but that's only because I don't have an o2 sensor so it's not running right (I'm working on it...) and I also drive the crap out of it and have wide tires... it should get about 30mpg normally.

I'm not really sure on the 4agze. I would guess lower, maybe low to mid 20s

[freakinbox]

Well if you are looking at gas mileage you are probably looking to save money. You might also want to consider the type of fuel you have to run. Such as with the 4age bigport using regular and the 4age smallport using premium. I can't speak for the 4agze or the 20v, I think the later 4agze required premium as well but I honestly don't know for sure. Maybe someone with those motors can tell you.

[eage8]

Originally Posted by freakinbox

Well if you are looking at gas mileage you are probably looking to save money. You might also want to consider the type of fuel you have to run. Such as with the 4age bigport using regular and the 4age smallport using premium. I can't speak for the 4agze or the 20v, I think the later 4agze required premium as well but I honestly don't know for sure. Maybe someone with those motors can tell you.

both 20Vs require premium. I would imagine so do all the 4agzes, but I'm not certain.

[Donald]

I was getting about 27mpg from my '89 GT-S with the 4A-GE engine.
I am now getting about 29 with the 7A-FE I swapped in. I also swapped in the 7A-FE gearbox which has a taller final drive than the one for the 4A-GE.

With the 4A-GE and matching gearbox my engine was turning about 3700 RPM at 70 MPH.
The 7A-FE engine and gearbox niow turn 3150 RPM at 70 MPH.
My driving routes and style are the same, about 40% expressway and always about 8 mph over the speed limit.
My previous AE92, a '92 sedan, would get about 29 mpg also.

I have to question anything over 32mpg from any Corolla with any 4A-XX engine, unless you are driving 90% highway, very conservatively, on flat roads with no traffic.

[eage8]

Originally Posted by Donald

I was getting about 27mpg from my '89 GT-S with the 4A-GE engine.
I am now getting about 29 with the 7A-FE I swapped in. I also swapped in the 7A-FE gearbox which has a taller final drive than the one for the 4A-GE.

With the 4A-GE and matching gearbox my engine was turning about 3700 RPM at 70 MPH.
The 7A-FE engine and gearbox niow turn 3150 RPM at 70 MPH.
My driving routes and style are the same, about 40% expressway and always about 8 mph over the speed limit.
My previous AE92, a '92 sedan, would get about 29 mpg also.

I have to question anything over 32mpg from any Corolla with any 4A-XX engine, unless you are driving 90% highway, very conservatively, on flat roads with no traffic.

With stock tire size (175/70/13) I would get 35 pretty easily. I once drove really easily to see what I could get and I got 39.5 mpg. when I put my 205/50/15s on with my new wheels I instantly dropped to about 25-28 mpg.

[Donald]

Originally Posted by eage8

With stock tire size (175/70/13) I would get 35 pretty easily. I once drove really easily to see what I could get and I got 39.5 mpg. when I put my 205/50/15s on with my new wheels I instantly dropped to about 25-28 mpg.

I concede. I have never run any of my Corollas with stock size tires, and that will make quite a difference.

[1991corolla4afe]

What about a turbo 4afe? What kind of mpg do you guys get out of them?

[freakinbox]

I personally found with the 205/45 r16's on the hwy I got better gas milage than the stock 170/70 r13's. But even with the worse gas millage in town with the 16 inch rims I'd have to say it's worth it since the handling and braking of the car are substantially improved.

[1991corolla]

Originally Posted by 1991corolla4afe

What about a turbo 4afe? What kind of mpg do you guys get out of them?

good question... i forgot to question the 4afe turbo (even though i'd still need a new motor to do this since mine is upwards of 330,xxx miles and would probably blow up)... lol ...

i do understand that the 4AFE's aren't meant for power, but she is my economical baby and i'm not lookin to make her silly fast anyhow... just to look and sound nice with a lil speed...

so if i swapped in a JDM 4AFE and turbo'd it, what kinda mileage/power am i looking at? keep in mind i live in california and the smog laws are sh*t here

[1991corolla]

Originally Posted by eage8

With stock tire size (175/70/13) I would get 35 pretty easily. I once drove really easily to see what I could get and I got 39.5 mpg. when I put my 205/50/15s on with my new wheels I instantly dropped to about 25-28 mpg.

damn... i was lookin into gettin some 15" enkei's or somethin like that on my corolla, with a sorta low profile tire, hopefully not too wide... so it'll hurt my gas mileage? if so, i guess i'd be like f*ck that and go with some lower profiles on some nice 13's and lower the car a bit

[freakinbox]

Originally Posted by 1991corolla

damn... i was lookin into gettin some 15" enkei's or somethin like that on my corolla, with a sorta low profile tire, hopefully not too wide... so it'll hurt my gas mileage? if so, i guess i'd be like f*ck that and go with some lower profiles on some nice 13's and lower the car a bit

That should also lose you some gas mileage as the tire would then have to spin more to go the same distance. Not being a rwd it's not as easy as switching out the differential for a different gear ratio to compensate. We used to put slightly over sized tires on our jetta's stock 14 inch rims and it improved the mileage noticibly

The issue with gas mileage on larger rims will depend on the type of rims you get and their weight. It all comes down to the rotating mass. The heavier rim causes the engine to work harder to get the wheels going. It's partially why even though people put the same size rims for their winter tires they lose gas mileage, because most people use steel rims for the winter.

Look at it this way. With a mix of intown and hwy driving (both with alot of hills, for those familiar with Ontario it was in Peterborough, hwy 115, hwy 401, and hwy 400, then from there to my house in Angus) I managed over 600 km to one tank. 600 km in miles is roughly 373 miles (rounding up to the next mile since I did alot more than that) with 14 inch steel rims which are heavier than my 16 inch aluminum rims (I know the tires on them equaled out to the rear 205/45 r16's except were 195's). It works out to about 28.69 mpg, keep in mind I am fairly heavy on the gas pedal and am ususally speeding on the hwy. Also it has a 4af which could use a tad bit of work, a carb doesn't overly help when you are running at 3000 rpm +. Like I said before, the improved braking and handling of the car are well worth the couple mpg you might lose. 175/70 r13's suck for hard braking and so fourth on dry pavement, they tend to like to roll over on the sidewalls during a harder than normal corner as well...