apie2546

Hey guys, simple questions I hope.
Went home this weekend and did an oil change to 10w40, and found my coolant leak which is a cracked wp. I also topped off my tires. I also removed my hood insulation. Drove on the highway back to where I live and managed 31 mpg? I'm pretty sure they're only rated to 23 on the highway. Should I be concerned? It doesn't run rough or act sluggish at all..

Also the cracked wp (which was replaced a few months ago) and specific reason for this? I'm buying a good one online instead of the Pep Boys one but its really concerning

Thanks!

cosmick

Where did you get 23? I've seen factory window stickers for these cars showing 25 MPG for the 5.7L with the 3.23:1 axle. With your 305 and 2.73s, I assume, those will give you more. Plus how slow were you going? Drafting behind bigger vehicles? Tailwind? The '98-'02 Z28s were reported to do 30+ MPG, with another 41 cubes, but about 200 RPM less at cruise.
The math says 31 is a realistic possibility for your car.

TTOP350

iTrader: (8)

A friend of mine consistently got 30-32 mpg on a long trips in his stock 91 TA vert with a 305 TPI, auto and 2.73 gear

apie2546

Oh okay. I got 23 from the epa website as a baseline. I thought it was unusual because the last time I did this same trip I got roughly 21mpg. I was a touch on the throttle on an open highway. Who knows. I'll take the extra fuel!

novaderrik

your car is using less gas and you were concerned about it???

PurelyPMD

iTrader: (3)

It's hard to use short trips to gauge mileage - just a simple mistake in the level of the fill can give you a wider variance. 100-200 miles should be the absolute minimum.

cosmick

I've caught the EPA website revising those estimates lower, they say it's because we drive faster now. Maybe so, but that doesn't mean a well maintained original car can't still do the old numbers at those speeds, and even then, many reported doing better than the window sticker EPA estimates. The EPA numbers have less than nothing to do with reality, they're all about political concerns.

dmccain

iTrader: (2)

I got 25.6 mpg on a long road trip with my L03 recently. Im sure now going from 2.73 to 3.73 im gonna lose some of that good gas mileage though.

apie2546

I was worried because I didn't want it to be lean lol

Usually half my trip takes half my tank of gas but I had barely used a quarter. Sounds good then. Also my car converter is just for show

cosmick

Just because 14.7:1 is best for emissions, and theoretically ideal, doesn't mean there's any worry, even at lean misfire. Only if it was that lean, then that hurts MPG.

apie2546

One of my friends cars burned a valve so I'm really cautious making sure fuel and air are correct