Pete47

Hi everyone I'm new to this Protege 5 stuff so please excuse me for any messups... I just recently purchased a used 2002 MP5 about a month ago and the reason why I brought it was for reliabilty and gas economy. My car doesn't feel like a fuel economical car! It sucks up gas just like my old 6cyl buick wagon.

I would like to know what are you other MP5 owners getting for gas mileage.
How much should I be getting? I put Chevron 91oct in my car, is this good or should I put a lower octain?
Heres a test that I 've been trying...I put the tripometer on zero with a full tank of gas and drive around untill I get a half-a-tank. When I look at the tripometer I'm usally around 110 miles average. Is this what I should be reading off the tripometer? Could it be that the octain that I'm using is burning up fast causing me to have a low mileage reading?

Please conduct this test and see where your car is at and reply back A.S.A.P. This would realy help us MP5 owners all out to see if are car is running right.
By the way how many miles are we suppose to get off of a full or three quarters of a tank avg?

Bellydawg

I average about 25-27 mpg using Shell regular, 87 octane. Usually fill up with over 300 miles showing on the trip odometer.

kgo

do you drive it mostly in city conditions or highway? i do about 70% city driving with auto trans and i get from 21-25mpg...i notice it being about in the 22's mpg. best i've ever gotten was about 27mpg. sad to say that something about this car just isn't that typical fuel efficient japanese car.

kgo

...forgot to mention that i use 87 octane.

Lazlo123

i don't have a p5, i've got a 2000 sedan dx... i usually get to 120 on the trip at 3/4 full. once i got to 120 miles before the gas guage even moved... i got about 40 mpg that time around... but normally i get about 33-35 mpg... but i doubt that'll help you any eh? sorry....

kargoboy

Well, first, our cars do get crappy gas mileage. I do mostly highway driving and have only averaged 27-28mpg.
Second, you shouldn't be using 91 octane in your car, use 87, that's what's recommended. All you're going to do is get carbon deposits on your plugs.
You should read the thread (I think it's in this forum) 'fuel inefficiency'.

Tom Slick

the only remotely accurate way to guage mileage is to divide your mileage by your fuel usage when you fill up your car (miles driven/gallons used). your guage is not acurate to measure off of. going off your guessing/guage method; let's say you use 4 gallons to get to 110 miles (percieved half mark), that's 27.5 mpg. now if you drove 15 more miles before you noticed you were at halfway and guessed again you'd think you were getting 31.25 mpg. see how much error that method of guessing has.
i get 26-29 with mostly highway miles on 87 octane, unless your car pings there is no need for higher octane.

Pete47

WOW guys thanks for the replies... Well I just went to the dealer and I looked at the fuel gauge when I got there and I wasn't quite at the half-a-tank mark. I looked at the mileage and noticed it was 147.8 is this where I should be at?

TOM SLICK: How do you know how many gallons the car uses? Is there a way to tell?

KARGO BOY:Why sohuld we use 87oct if 89 and 91 is better? Isnt 87oct the fuel to be used for go-karts and lawn mowers? I just recently put Z-max lubricante in my car and it really took away alot of the engine noise. When you put the lower octain, does your car ride smooth and with no vibrations? Have you tried and felt the diffrents between diffrent gas? W/B

kargoboy

I don't profess to be an expert in this area, I'm not a mechanic or engineer, that's the main reason I joined this forum.
The only thing I know for sure is that your engine will not benefit fom higher octane.
The higher the octane, the higher the detonation point. That means you need more compression to detonate the fuel, which we don't have, at least not the stock engine. So, you risk unburned fuel and hence, carbon-deposit build-up.
Anyone out there please correct me if I'm wrong!

Tom Slick

when you fill up your car the gas pump tells you how many gallons of gas you put into it (used). if you know how many miles you have driven since the last fill up then you divide your miles by the amount of gas the pump tells you. i use one of the 2 trip meters for this mileage calculation. just zero it everytime you fill up with gas. this is all assuming that you fill the tank to full when you are checking your mileage. you can't use it if you "just put $5 in" each time

that takes the guessing out of calculating your mileage and is reasonably accurate.

you CANNOT calculate mileage from guessing what the guage is reading. just being on a slight hill makes the guage read wrong.

rednor60

I'm a new P5 owner and have been lurking for the last few weeks. After reading about the gas guzzling, I was puzzled because it's not what I've been experiencing. It's been a fun ride to this point.

I purchased a 2003 P5 (white, manual) a month ago with 19 miles on it. I have a 20 mile RT 50/50 commute, and just went on a 600 mile RT wild ride on Highway 1 in Central California. With only 1700 miles on my car, I've been getting 26-29 mpg and avg 30+ mpg on Highway 1, and I was pushing hard, rarely going above 3rd. I was using a generic 87 octane (California), but the last 2 weeks went to 89. I've been filling up at over 300+ miles on the OD. Should I expect to get better mpgs after break in? Will check in after 15k and 30k.

BTW, I got the leather shift **** (the one from the stock M3) from Rosenthal Mazda for $72. My local Parts Department was asking $213???!!!! Screws right on and looks great with the aluminum base plate in my car. Just enjoying my new ride. Cheers.

rednecks_r_us

I average 28 MPG with 91 octane. (Miles driven divided by amount of fuel at fill up.)

I have the MP3 ECU that has the advanced timing so I have to run the higher octane. I also have wider than stock tires that will use more fuel.

stealthscotty

Kargoboy is half right on theoctane question. Higher octane fuel is more resistannt to detonation, but isn't likely to go unburned or leave undue deposits behind in your combustion chamber. Premium fuel is typically loaded with detergents and additives designed to clean deposits from your engine, any left behind probably the result of poor quality fuel(additives are added to each tanker based on the retailer requirements and subject to human error) or worn/improper spark plugs.
Detonation is really only a concern in heavy vehicles or in high heat applications (turbos). Our cars are light enough that the benifits are marginal. The ECM will advance timing as far as possible before detecting detonation(to a point) so as to make the most power on the least fuel. A stock ECM is usually maxed out before anything better than 87 octane is needed. An MP3 ECM using more agressive timing advance curves can use higher octane, but won't require it. On cheap gas the ECM will back off timing and simply slow the car down. If you have a stock Pro, save the pennies and buy cheaper fuel.
I have a 2002 with 50K and routinely get about 26 mpg. I can squeeze 30 if I try but it means I have to keep my foot out of it. I'd rather enjoy my car. .
Pete, Ignore the gas gauge and look at the speedo. It's more fun!

Pete47

StealthScotty: I guess your right. I need to enjoy my car more and have fun around the curves... What I'm going to do is let the gas in the car wich has 91 octain burn out, and I'm going to start useing 87. I'll let every one know how it runs.
Thanks.....guys.

kargoboy

Thanks for the help explaining, Stealth.