Fuel economy questions?

[Rebello240zx]

Hi I just aquired a fwd 92 loyale wagon. I'm cuirous as to the best way to attain better fuel economy. I get about 31 mpg, which is good but my dad's nissan maxima "95" gets 30.2 mpg. I assume the close numbers are due to the fact of the soob rpm at 3k and him being at 2k. Is their anyway to change the 5 speed trans with a different, taller geared one? did subaru make a trans with taller gears? or is it possible to convert it to 4wd then remove the front shafts and swap with another r160? I know nissan used the same r160 diff (made by fuji heavy industry) could i use one of those or do they simply not go lower then 3.90s?

The car on the freeway going 62 mph does 3k rpm does that sound right?

car currently has 3.90s

I'm a datsun guy and i am not fimilar with subarus what so ever warnings, help, or quirks you can let me know about would be helpful and much appreciated. I have already dealt with the infamous timing belt, right cv axle, valve cover leaks, trans leaks, and an intermitent starter problem.

thanks to all, This site has been very helpful, the people seem real nice and just crazy about subarus. just what I'm looking for. keep em running

[Snowman]

Actually, I've found that the EA82 is happiest around 3000 rpms. Peak torque is 2800, and you should generally cruise at just above that point. Below that, they tend to lug, reducing fuel economy substantially.

 

Run a couple bottles of Chevron Fuel System Cleaner through it and see if your MPG doesn't improve (that stuff works wonders).

[WJM]

All SUBARU engines love to rev. They enjoy being above 3k.

 

My EA82 Turbo enjoys 3500RPM+ when cruising.

[Alex C]

My EA81 turns 3900+ a 65mph(when it ran), but its also a 3AT.

 

Alex

[mtsmiths]

Run your tires at 38 psi, better mileage, and they'll wear better too.

 

My 2.2 Leg AT cruises at 2850 at 70.

[NorthWet]

You could swap over to the 4-speed automatic, which would drop the cruise rpm about 800-1000. Not exactly a popular swap, however.

 

The Nissan R180 and possibly even the R200 should bolt right in. I have some links to pages that list the various Nissan diff ratios.

 

Another possibility is to run taller wheels/tires. Not exactly easy, but doable.

 

BTW, I have a '71 510 with an z20+5speed, R180, and corvair rims. fun...

[Syonyk]

Wow. You're complaining about 31mpg?

 

Anyway, as said above, I'm not sure you'd gain much by turning the engine significantly slower. They're kind of gutless down low, and you'd have to really be lugging it to keep the speed up. In addition to using more gas, that's torture on bearings.

 

You've done a full tuneup, right? Plugs/wires/cap/rotor/O2 sensor?

 

-=Russ=-

[Bucky92]

My 92 Loyale FWD 5 spd gets around 38-40 mpg...3300 rpms at 73 mph (any more and it shakes itself to pieces) and thats with a bad EGR (havent put the new one in yet).But his previous owner used him for a commuter car..all highway long distance.

 

I dont know why he does so welll but I am happy he does...But I still wouldnt complain getting 31mpg

[Hank Roberts]

> Tire pressure

This may be different for different models, but I've seen warnings elsewhere that for the GL series like my 1988 turbo, higher tire pressure will wear out the middle of the tires fast, and to stay with the factory specified (which I think is 26 -- but don't trust my memory, I don't!).

 

Now I've only had the 1988 GL turbo for, what, three weeks now -- 240k miles on the body, 60k miles on a swapped engine -- and made one long trip with it.

About 200 miles on the freeway, 30 on 2-lane pavement, and maybe 50 on steep gravel Forest Service mountain roads in mostly 4wd low gear.

 

21 m.p.g. so far overall. Not what I"d hoped -- but it's back in the local Berkeley shop for a Check Engine (34, EGR solenoid) light that has persisted through three different mechanics' attempts to solve it. Makes me suspect something else is wrong in there.

 

I'm very glad to see the thread started, I'd been thinking I really wanted to know what kind of mileage, RPMs, tire pressure etc. others report here.

[Snowman]

Tire pressure is 32 in front, 28 in back unloaded. Raise the back to 32 when loaded. I've run mine around 32-35 for years and they seem to wear pretty evenly, aside from the outer edge wear on the front tires that comes from the stupid positive camber built into these cars.

[Rebello240zx]

Ok so let me get this straight. It's better if im above 3k then below it? I have been trying to go as slow as possible to rev lower. (as in 2700 rpm 55mph behind semi trucks) and from the plentiful responses it seems that is the wrong course of action. what about launching the car? i shift at 3k should i rev it up more or what? Anyways I'll try 3300 and see what happens. And yes wires, cap, rotor, and o2 are brand new. Thanxs to all for the prompt responses.

[royboy159]

Hey Rebello---Shifting an EA82 at 4000 rpm doesn't have much effect on mpg. 4000 rpm in 4th, 3200 in 5th will get you 65mph. Uping tire pressure in the snowless months can get you 35 mpg without problems.

[Snowman]

I've always found that my car gets the best fuel economy between 60 and 65, but your results may vary. Shifting around 3000 is probably okay, but the car really doesn't care if you rev even to 4500 before shifting. I usually shift around 3500, and it seems to give the best results as far as performance and economy.