ZR1 Gas usage

[Robert Z.]

I have a 94 ZR-1 and my friend has a 92. When we travel together he will out mileage me on all trips. We have the same rear ends and transmissions the only difference is mine is a 405 and his is a 375 and the colors. Any ideas as to why this happens would be appreciated. Ex. a 250 mile trip I use 13 gallons and he will use 10, this is following the posted speed limits
Thanks
Bob

[Terry M.]

Re: ZR1 Gas usage

Are you both using cruise control.

Once upon a time I worked in a situation where we drove pick-up trucks to get to our job location. Occasionally we would ride together. One of my colleagues continually pumped the gas pedal when driving. I am sure he was unaware of it, but I wouldn't ride with him driving. It "drove" me up the wall.

[Clem Z.]

Re: ZR1 Gas usage

my suggestion the next trip trade cars and then check the mileage

[Chuck G.]

Re: ZR1 Gas usage

Are you both using cruise control.

Once upon a time I worked in a situation where we drove pick-up trucks to get to our job location. Occasionally we would ride together. One of my colleagues continually pumped the gas pedal when driving. I am sure he was unaware of it, but I wouldn't ride with him driving. It "drove" me up the wall.

I can relate to that. Have a friend who drives the same way.

On the Interstate roads, he's constantly between 50MPH and 70+MPH, "depending". On flat straightaways, he doesn't hold a constant speed. He's constantly goosing the throttle to get back "up to speed".

It's worse on hills, where he REALLY slows down as he climbs the hill.

Drives me nuts, and actually makes me a bit car sick to ride with him.

Chuck

[Robert S.]

Re: ZR1 Gas usage

Are both the 92 and 94 engines unmodified? It's common for ZR-1's of that era to have an aftermarket chip. These typically alter air/fuel ratio and timing. A prior owner could have installed without your knowledge.

[Joel T.]

Re: ZR1 Gas usage

Bob;

I would agree that it probably has to do with driving "style".. What I have found to be the best way to get decent mileage is simply to use the cruise control.. I set mine to 3 miles over the limit and just let it run... Wife and I took the new Z06 for a 500 mile run recently and it achieved (per the computer) 27.2 MPG for the round trip... not too shabby!

[Tom H.]

Re: ZR1 Gas usage

Are you absolutely certain the rear end ratios are the same ? It was a popular mod back in the day to change the gear. Are the RPM's the same on both engines at road speed ?

[Robert Z.]

Re: ZR1 Gas usage

Neither one of us use cruise control but my car won't hold it if I am using on any type of hill so it is not very practical. I have the most luck closing the gap on our gas mileage if I stay in 5th and he is in 6th. Would there be a difference in the injectors in the cars, though I would think that my car would run richer just based on the difference in engines?
Thanks
Bob

[Clem Z.]

Re: ZR1 Gas usage

Neither one of us use cruise control but my car won't hold it if I am using on any type of hill so it is not very practical. I have the most luck closing the gap on our gas mileage if I stay in 5th and he is in 6th. Would there be a difference in the injectors in the cars, though I would think that my car would run richer just based on the difference in engines?
Thanks
Bob

if you did not buy the car new i agree with the above you have no idea what was done to the car.

[Patrick H.]

Re: ZR1 Gas usage

Neither one of us use cruise control but my car won't hold it if I am using on any type of hill so it is not very practical.

Thanks
Bob

I'd think that there is something not quite right about your car if that is the case. No reason that is shouldn't run fine in 6th on cruise unless you're going through the Rockies or some areas of the Appalachians. While a somewhat different car my 08 will cruise all day long in 6th as will my Dad's 1992 with a 6 speed.

Patrick

[Tom H.]

Re: ZR1 Gas usage

I'd think that there is something not quite right about your car if that is the case. No reason that is shouldn't run fine in 6th on cruise unless you're going through the Rockies or some areas of the Appalachians. While a somewhat different car my 08 will cruise all day long in 6th as will my Dad's 1992 with a 6 speed.

Patrick

Totally agree ! I've driven many miles in many ZR1's and have never had issues with the cruise holding in 6th.

[James C.]

Re: ZR1 Gas usage

Worrying about gas mileage kind of defeats the intent of a car that has a rear window decal that says "Life begins at 180 mph" though. These cars live to be driven hard. Jim

[Robert Z.]

Re: ZR1 Gas usage

Good Point!