Hello all
I am new here and am seriously considering buying a 92-93 SC300 I6. The only problem I have is the mpg this car gets, yes I understand the "if you wanna play, you gotta pay" theory.

But I truly belive I will love this car it has pretty much everything I am looking for right now at the right price except the fuel economy. My current vehicle is a 97 Honda CR-V that gets roughly
22/city 25/Hw and that is acceptable. So my question is what can I do to bump up the mileage on a SC300? I have poured over the forums reading as much as I can, as well as the net without much avail. So far I have come up with

1. Performance exhausts
2. Headers...........except I can only find them from Xerd (if you know from anywhere else pls let me know.
3. Pulleys............Not underdrive, and not crank, just water pump, alternator etc
4. Intakes............ CAI, Drop ins, all with pros and cons

Thats all I can really think of for now and of course a conservative driving style, my current driving is mostly city with about two 300km drives a week.

Any help would be appreciated. Sorry for any typos Its 7am, still up from reading forums and internet research.

 

k&n cone get an adapter from autozone drill holes to match the MAF it got me up to around 20 and thats with the stock exhaust

 

You are likely not going to out-economy your light, four-banger Honda with the heavy, iron-block I6 in the SC300. But, your numbers will not be far off. The SC300 can definitely get you over 20 on the highway and over 15 in the city.

A rear end swap from an SC400 would be very cheap and easy as far as increasing economy. The SC300 has a 4.27 final drive ratio to the SC400's 3.92 final drive ratio. The SC400 rear end would lower your rpms ~10% at any given speed, which would give you the chance for better economy - especially on the highway (although at the expense of a little off the line performance). SC400 differentials can be had for ~$200 off the classifieds, and the surgery could be done in your driveway with basic auto tools.

 

What about having one as a second car? The MPG ratings of the two cars aren't that much different, although the Honda obviously is a little better on gas. I'm considering getting some little 3-cyl Geo or 4-cyl Toyota/Honda as a second car to drive when I want and to save on gas, and wouldn't have to get out the nice SC in bad weather, etc. Although paying more to insurance doesn't sound very good to me, but at least insurance is a lot cheaper now that I'm over 25. Gas prices are just ridiculous, especially premium.

 

some other mods you can do is basically clean out the engine..do some seafoaming, spark plugs, spark plugs wires, ground wires, and also, lightening the car..maybe change out the seats to something lighter, cf parts, etc..wont do too much..but its a lil something

 

I removed my spare tire. Thing is like 45-48 lbs. Less rear wheel traction, I guess is the disadvantage. Not sure if it's a safety issue, if the SC needs all the traction it can get (in bad weather conditions) or if it is fine without the extra spare tire/wheel weight. I assume the less weight the better.

 

driving habits can affect your mileage better than any type of mods

 

great thread and oldy but a goody

 

very true...if i would stop driving like an ***, i would stop getting 10mpg city

 

Do a basic tune up, And tho's numbers should improve

 

its had a full tune up...new cats, new o2 sensors, plugs, wires etc...

i just cant keep my foot off the gas pedal

 

Less weight helps everything. Acceleration, braking, handling, gas mileage, etc. Also, less weight = less stress on parts. For example, I'd imagine your car still has the car phone stuff in the trunk hidden under the lining, enough little things like that and it adds up.

 

Driving habits are where you'll see your largest gains. Invest in a vac gauge. or if your going NA-t in the futire just buy a boost gauge w/ vac reference. Keep the gauge no lower than 10 psi of vac pressure. Doing this the car will accelerate about as quickly as your average semi. I get soem odd looks sometimes but it pays off big at the pumps.

Once you have the grandma driving habits down all the above will help a little. MAking sure your car is tuned up and running well the try these.

1.) freeing up intake and exhaust
2.) getting the car as light as possible.
3.) making sure all your tire pressures are up
4.) greasing your wheel bearings with low friction synthetic grease.


I swapped out to a 3.76 rear pumpkin from a supra. And run max tire pressures on all 4 of my tires. While I know this isn't the best for handeling or wear it also makes a pretty large MPG difference. Last time I checked my MPG I was averaging 21mpg on a tank full. This is with a 18 mile highway cruise to and from work with a little city driving.

 

i get 22 mpg so far on my 92 Sc400.
...

Just do a good tune up n drive slow =]

 

beside your tune up, tire pressure and all that good stuff, make sure your car is aligned properly, that should also help. Definitely driving habit is whr it is. Im ready to do my tune and hope to see some improved numbers. good luck.