Stock 1jz Cressida MPG numbers

[Cruiserhead05]

I'm running a fairly stock 1jz in my 89 cressida. It had a full 3" exhaust and i was averaging 20mpg or so. Recently i installed a generic 3" cat to pass inspection, since then i've been averaging 25-29mpg. I checked my math and have run 3 tanks threw it. Do these numbers sounds too good to be true?

 

[10secdream]

Wow thats pretty good MPG you got there. I am assuming that average is with mostly highway driving.

 

[Cruiserhead05]

Yes. 100% highway doing between 70-80mph i got right at 29mpg. I was shocked and checked my math several times. Keep in mind that was rarely hitting any kind of boost.

What are some more typical numbers to see with 1jz supra's or cressidas

 

[10secdream]

Yes. 100% highway doing between 70-80mph i got right at 29mpg. I was shocked and checked my math several times. Keep in mind that was rarely hitting any kind of boost.

What are some more typical numbers to see with 1jz supra's or cressidas

I get about the same just purely highway driving. In the city I usually get around 20-22mpg.
My mods are full 3inch exhaust, intake, and an HKS intercooler.

 

[tlo86]

you get the best MPG change from driving habits

 

[viperkillertt]

I'm running a fairly stock 1jz in my 89 cressida. It had a full 3" exhaust and i was averaging 20mpg or so. Recently i installed a generic 3" cat to pass inspection, since then i've been averaging 25-29mpg. I checked my math and have run 3 tanks threw it. Do these numbers sounds too good to be true?

haha, i have the wrong ecu. Mine wont get close to those numbers. Blitz just tuned it to flow too much fuel, even on the freeway. I get 22 if i am lucky on the freeway. Around town is 15-18. I drive a supra though. I am very jealous of you guys!!!

I am really having a hard time understanding how a exhaust restriction like a cat is increasing your fuel mileage 8 points. That sounds crazy.

 

[tturnpaw]

i around 18-20 in the city, about 24 freeway in the supra with a mines ecu. viper-do you have a large flat spot or hesitation when you roll by 3krpm?

 

[viperkillertt]

i around 18-20 in the city, about 24 freeway in the supra with a mines ecu. viper-do you have a large flat spot or hesitation when you roll by 3krpm?

Nope, not that i know of. You can check out my dynomap on my page. http://spokanesupras.com/Josh.aspx It looks pretty smooth to me.
My only issue is the ecu runs stoic at all times, even cruising at 55 on the freeway, it wont go above 14.7AFR.

 

[tturnpaw]

Nope, not that i know of. You can check out my dynomap on my page. http://spokanesupras.com/Josh.aspx It looks pretty smooth to me.
My only issue is the ecu runs stoic at all times, even cruising at 55 on the freeway, it wont go above 14.7AFR.

Weird...mine rides on 14.8-15.2 cruising. I think my tps is going out, sometimes it feels like a flat powerband like im only giving it 3/4 throttle and others it tears down the road.

 

[tturnpaw]

just checked your #s josh, i dont think mine does it at wot. only at anything below 1/2.

 

[viperkillertt]

just checked your #s josh, i dont think mine does it at wot. only at anything below 1/2.

Weird, yeah, mine is very smooth. I havent felt anything like that.