365 miles. ONE TANK.

[rx7tt95]

I can't believe it either.

Yep, after switching over to the VX as the daily driver, I took down my start miles for my last fill-up. I have to keep track of miles for mileage reimbursement. To my surprise, my total mileage for the last tank was 365 miles. One caveat, I almost ran her dry. She stumbled about 1/2 mile from home when I turned around as I'd forgotten my wallet at home. Fate?

Anyway, I'd been driving a 2005 Mitsubishi Evolution VIII (turbocharged 4-cylinder, AWD, about 300hp/300torque at the wheels) with a few small modifications as my work vehicle. As gas prices rose sharply, I began to drive like I owned it and began to experiment with how to get the best mileage out of the vehicle. I'm reimbursed .30 cents a mile (pitiful) so it's worth my effort. While I had been short shifting prior to peak torque (and probably peak VE), I noticed my mileage was about the same as if I'd accelerated with positive boost (not pushing it hard, but decent acceleration). Essentially I was lugging the engine in many situations. So I began shifting at 4K rpm, 500 rpm above peak torque and I stayed well within the vacuum zone and out of positive boost pressure. Revving the engine a bit higher helped me stay out of the lower rev range and thus lugging the engine when I switched into a numerically higher gear. My mileage went way up. Where I'd been struggling to get 260 miles out of a tank, I was now easily at 300. Modifying my driving a bit more, I'd see over 310 to 320 in city driving on a regular basis.

In the VX, there's really no way to control shift points and vacuum pull (which determines how much fuel your injectors push) like you can in a manual transmission vehicle. So I skipped the "normal" transmission mode and I leave it in sport. This is mostly because even under light acceleration, it tends to use higher revs, lower gear and thus it puts less load on the engine. Pulling from low revs in a higher gear uses more fuel.

I also coast to stoplights/signs. I don't accelerate hard, but I don't hold up traffic. A/C is on all the time (it's Florida) and I drive with my lights on. I also try to find routes that don't have as many stop and go situations and usually, I avoid the highway and will take a slower road with no traffic lights to reach the same destination when possible. Also, I use cruise control whenever I'm able. Every time you accelerate, the injectors squirt a bit more fuel than needed acting like an "accelerator pump" on a carb. Keeping a steady throttle reduces overall fuel load over time.

I have put the stock intake back on where previously, I had an Injen on there. I did not take a mileage reading with the Injen on for a full tank of gas as I switched it out mid-tank for the stocker.

I have an Aero exhaust en route. I should be able to run through one more tank before I'm able to put it on just to verify. Will of course report back after I install the new muffler. I may end up replacing my catalytic converters depending on how good/poor they look. I thought for sure they'd be toast by now but I guess not.

Also, I recently had the transmission fluid changed along with the filter. Replaced the front and rear differentials and the TOD. I used Royal Purple in the diffs, normal weight, and Castrol synthetic in everything else. I have a 1999 so I have the 16" wheel package and I have the rear seats removed although any loss in weight has been regained with all the camera equipment I carry in the car. The car is over 120,000 miles now. I thought about switching to 18" rims but I may not do that now. I have stock-sized tires on there, Firestones, with 34psi of pressure all around.

So...I'm hoping to hit 375 WITHOUT running her dry after the exhaust changeout. We'll see..I know others have reported mileage loss switching mufflers out. There are lots of reasons why this occurs and there is good reason why, if the car is driven in the correct manner, freeing up back pressure on the exhaust side will work to improve mileage as well.

[Joe Isuzu]

very impressive, almost 100 more than I get and the only thing I see you as beating me on is 16" vs 18" rims, can't imagine it makes THAT much of a difference
don't know if I particularly agree with your stance that running the engine harder in a lower gears is better than running it more relaxed in a higher gear, yes, lugging the engine is bad but in my eyes, that's why we have OD, to get a more relaxed engine and therefore, better gas mileage
used to be most sports cars got better top speeds out of 4th gear than 5th as 5th was truly an economy gear, just my thoughts..

[taylorRichie]

I've hit that a couple times (sans lift).

I always thought it was weird when people said they could barely get 250... But now I'm in the 250 mile gang :D

Time to run some acetone... Of course I only drive the VX about 40 miles a week these days. Commuter vespa the rest of the time.

[etlsport]

i believe it... had my vx in the city the other day.. and anyone whos ever driven in philly traffic knows.. sometimes you gotta hit the go pedal HARD and i was driving the crap outta the ol' girl.. 5000+ rpms etc... once i got away from the city to check my gas mileage (scangauge) i was astonished to find i was at 16.5mpg.. a little higher than when i REALLY baby the throttle... since then started revving hard and fast then letting it coast the rest of the way.. seems to help my mileage

[rx7tt95]

When I'm in sport shift mode, I don't accelerate hard. I accelerate just as anemically as if I'd been in the normal shift mode. Small throttle openings at higher revs will put less load on the engine than small throttle openings at low revs (lugging it). If you had (or have) a vacuum gauge in your car, you could visibly see the difference between the two. There's very little "control" of this with the VX and it's automatic however. It's a very small window of benefit from what I can tell.

One other thing I do that I forgot to mention is put the car in neutral at stop lights while waiting. Again, you're loading the engine less.

[PMFog]

This Spring I have been running in Power mode just to run with different shift points in the transmission (1 flush and fluid change so far at 60K) now that I've reached 100K. Also replaced the PCV valve and have noticed I am getting better mileage. Couldn't say which made how much of the difference so I'm happy to see a more technical analysis.

PMFog

[nfpgasmask]

Before I lifted and added bigger meats I was hitting 350 a tank. Now, after the lift, I am getting about 260 (that is, if I compensate for my ODO and Speedo offage). So, the burden of the lift and bigger tires and the extra weight on my roof rack costs me about 100 miles every tank....which TOTALLY sucks.

Bart

[Techy-D]

I've been watching the MPG's on the Scangauge (both instant and trip) + Throttle Position. It's changed my driving habbits and does agree with some of the things here. I've found that a moderate acceleration (even a bit of a hard acceleration), with a small letup (allowing it to shift sooner) and then back into it a bit till I get to speed, then backing off to where I can bearly hold that speed or even loose speed slowly, has been the trick for my longer drives (slow accelerations just seem to prolong the lower mpg's). Also, Letting off the gas and coasting sooner and for longer times does make a lot of difference on the scangauge. My real Average MPG killer is the slow bouncy gravel road where I seem to do 6 or 8MPG.
I've been able to get my daily average up to 18mpg if I'm not in a hurry and pay atttention (not pressing the pedal anymore than absolutly necissary to keep going will help me 3 or more mpg and there is really no noticiable speed increase or decrease). When I'm late and hurry to work, I seem to get about 14.5mpg.
All said and done, I consider it a game and a research project, with financial rewards of course (and a bit more relaxed, peace of mind time on my commute) :)

[woody]

I consistantly get 290 around town and I don't drive like a granny. My Fiance lives in Memphis (me in Dallas) and I average 330 per tanks with a full load of gear, 2 dogs, sport mode and 80 to 85 mph..
I think my guage is a little off...I get around 120 miles when it is showing a half tank and then easily pull another 200 on the other half...
I've done nothing except add a Borla Muffler...interested to see when I add my cold air intake and a few other goodies!
Cheers
Woody

[So-CalVX]

I've been getting between 290 and 310 lately... my last tank (i just filled up a minute ago) was all in town driving and i got 305 with a 20 gallon fill, then my tank b4 that was mostly in town with a trip to Thousand Oaks, then Montecito, then Thousand Oaks back home to Ventura, which put me at 320 on a 20 gallon fill.....

it has made me happy considering i lost my job at honda and gas prices continue to rise...

[woody]

sorry to hear about your job brother VXer. Maybe there are some other VX folks in your area that are looking for folks!! Shoot you never know...this is a pretty tight site!!
Woody

[rx7tt95]

I received my AERO 2525XL muffler today and I was shocked at how small it was. I was expecting this big honkin' tube but it's actually quite small. I really really hope this thing isn't too loud. It looks like it will be. I was actually riding around today thinking just how quiet the VX really is with the stock muffler/airbox. I did manage to get bi-xenon HID's installed last night although I haven't had a chance to actually use them at night.

[Joe Isuzu]

I received my AERO 2525XL muffler today and I was shocked at how small it was. I was expecting this big honkin' tube but it's actually quite small. I really really hope this thing isn't too loud. It looks like it will be. I was actually riding around today thinking just how quiet the VX really is with the stock muffler/airbox. I did manage to get bi-xenon HID's installed last night although I haven't had a chance to actually use them at night.

good luck on the muffler, I learned the hard way on that and am still trying to figure out if I can live with my new aggressive sound...

[rx7tt95]

Does it drone a bunch in the cabin? I heard the video clip of it and it didn't sound bad at all...

[Joe Isuzu]

I don't have the same style muffler that you do, I have a flowmaster

[VehiGAZ]

I learned the hard way on that

You and me both.

[blacksambo]

You folks need to try Lucas gas treatment. (No, I don't own stock in the company.) It costs $10.00 for 5 tank fulls and you get 40-50 more miles per tank. A no brainer at today's gas prices. Also, try 39 lbs of tire air pressure, it helps our mileage, as well. Less roll resistance. Keep coasting and taking it out of gear at lights, but keep the PRNDL linkage well lubed with lithium grease.

[JHarris1385]

I have 356 on mine right now, the light is on but I am lifted. I also am doing the acetone mixture.

[kodiak]

I get in the mid to upper 300 all the time now. The best tool you can buy is a Scan Gauge II, it really helps you monitor you driving and helps you keep the power consistent on the freeway. Its like a game to try and keep it at 20 mpg.:p

[JHarris1385]

I actually just filled up 20.20 gallons with 361 on the tank....I used to barely get 270.

[Jolly Roger VX'er]

Just got 356 miles out of tank with low-fuel light on steady for about the last 10 miles. I was going to go for the gold (366 miles) but chickened out....bok bok bok...cluck....cock-a-doodle-doo.

[LittleBeast]

You folks need to try Lucas gas treatment. (No, I don't own stock in the company.) It costs $10.00 for 5 tank fulls and you get 40-50 more miles per tank.

I honestly did not believe you as I have tried these things before with very little effects, but I just got 2+ more MPG on my last trip using the Lucas Fuel system additive, thanks, I will be trying this out some more.

[Joe Isuzu]

ok, I'm sick of being the low man on the totem pole on this, I've not scratched 300 except for a couple of times and typically ALWAYS get 270 on a tankful, it's annoying hearing all you people getting mid-300's
grrrrrr!!
I was going to mess with the spark plugs to see if they're in need of replacing but I will also try the lucas tx first, ANYTHING will be an improvement here....

[JHarris1385]

Change fuel filter. And then tell me about the exhaust you have coming out at idle?

[Joe Isuzu]

fuel filter changed at 90k

[Joe Isuzu]

say, here's a thought I had this morning
I'm running at factory settings for the tires which I believe is 30, I'm certain it's low to try and improve the ride or to improve your off-road ability (guessing on that one)
all you lucky dogs who are getting such great mileage, what PSI are you using in your tires?
that would be an easy fix if everyone is running higher than stock, I realize the higher the pressure the better your mileage but also the more quickly it wears out the middle of your tire so I'd like to find a happy medium if everyone IS running increased pressures

[taylorRichie]

I ran about 38 on the way to moab, and got about 375 miles.

I now run 35 on my 33"s because I don't like the way it handles with 40. I only drive 3 miles to work, and take my Scooter on most days.

I fill up about once a month.

[Joe Isuzu]

I ran about 38 on the way to moab, and got about 375 miles.


Was that on your OEM 18's? Or the larger sized-tire you have?

[taylorRichie]

Sorry... that was on my 18's :D I haven't seen 250 since I've gotten my big wheels/tires. But I've also done city driving only, 3 miles at a time. I'm pretty sure with a good mix of highway city I'd be around 300. I'm at like 230 right now with 1/4 tank left, and that was with ~120 of highway. (and 38PSI)

[Joe Isuzu]

ok, BlackSambo wrote earlier that he does 39, you do 38
Do you notice any increased tire wear?, I've had my Kumho's for about 10k I reckon and can't see much wear at all,
I think I'll experiment going up to 35 at the next refill and see what kind of difference I get

[JHarris1385]

Any word on your exhaust?

[Cobrajet]

ok, BlackSambo wrote earlier that he does 39, you do 38
Do you notice any increased tire wear?, I've had my Kumho's for about 10k I reckon and can't see much wear at all,
I think I'll experiment going up to 35 at the next refill and see what kind of difference I getI generally run 38 in my Kumho's (265-60/18), and get in the mid-300's when my NOVA commute allows me to do the speed limit. I got 43,000 miles on my last set of Kumho's, and the fronts were worn smooth all the way across. I love to haul around corners, so wearing out the fronts is not surprising. (Yes, I do rotate the tires...occasionally.)

[Joe Isuzu]

Change fuel filter. And then tell me about the exhaust you have coming out at idle?

I forgot to address the exhaust question, I guess I didn't quite understand your question. If you're talking about the rev's maintaining a high number even when you lift off the gas, that got remedied by bleeding some surplus tranny fluid. It's still not the way I remember (could be my memory) it but it's definitely better than what it was. Exhaust is still loud to me but I'm learning to adjust for the time being.
I got the gas tx last night and pumped up the air pressures. Keeping my fingers crossed.

[Joe Isuzu]

I generally run 38 in my Kumho's (265-60/18), and get in the mid-300's when my NOVA commute allows me to do the speed limit. I got 43,000 miles on my last set of Kumho's, and the fronts were worn smooth all the way across. I love to haul around corners, so wearing out the fronts is not surprising. (Yes, I do rotate the tires...occasionally.)

thanks Gregg, that's encouraging about the mileage you got. I got the tires from the Tire Rack 2 years ago on the way to Jekyll and they weren't terribly bad.

[JHarris1385]

I meant as far as what is coming out of your tail pipe. Anything abnormal or too much?

[etlsport]

I forgot to address the exhaust question, I guess I didn't quite understand your question. If you're talking about the rev's maintaining a high number even when you lift off the gas, that got remedied by bleeding some surplus tranny fluid. It's still not the way I remember (could be my memory) it but it's definitely better than what it was. Exhaust is still loud to me but I'm learning to adjust for the time being.
I got the gas tx last night and pumped up the air pressures. Keeping my fingers crossed.

I think what J is getting at is... does your exhaust seem like its coming out too fast or smell rich of something (more specifically does it smell like fuel?) if it does, a likely culprit would be your fuel pressure regulator, common problem and typically replacing it is good for 2-4 mpg

[Joe Isuzu]

I think what J is getting at is... does your exhaust seem like its coming out too fast or smell rich of something (more specifically does it smell like fuel?) if it does, a likely culprit would be your fuel pressure regulator, common problem and typically replacing it is good for 2-4 mpg

Wow, thanks Etlsport, we would have gone a couple more posts before I figured that one out! At 90k+, it could be anything, so the fuel pressure regulator may be bad, haven't smelled the exhaust in a while, honestly I try to hold my breath around it, as far as I remember it smells like exhaust to my simple nose, I will pay more attention next time to see if I smell anything odd
For that matter, how easy/hard would it be to replace if I wanted to just do it anyway? I'm figuring with the mileage it wouldn't hurt

[JHarris1385]

Change fuel filter. And then tell me about the exhaust you have coming out at idle?



As in the amount and color....

[etlsport]

Wow, thanks Etlsport, we would have gone a couple more posts before I figured that one out! At 90k+, it could be anything, so the fuel pressure regulator may be bad, haven't smelled the exhaust in a while, honestly I try to hold my breath around it, as far as I remember it smells like exhaust to my simple nose, I will pay more attention next time to see if I smell anything odd
For that matter, how easy/hard would it be to replace if I wanted to just do it anyway? I'm figuring with the mileage it wouldn't hurt

couldnt hurt.. the part will cost you less than a tank of gas (about 50-65 bucks depending where you get it)

getting a set of snap ring pliers will make things easier.. i got mine for 20 bucks at sears with a whole set of tips for them

another piece that will make it much easier is a 6mm allen wrench that is cut shorter.. i think i have one laying around that i used when i did mine.. pm me your info and ill find it and mail it out along with the instructions i used

[Joe Isuzu]

couldnt hurt.. the part will cost you less than a tank of gas (about 50-65 bucks depending where you get it)

getting a set of snap ring pliers will make things easier.. i got mine for 20 bucks at sears with a whole set of tips for them

another piece that will make it much easier is a 6mm allen wrench that is cut shorter.. i think i have one laying around that i used when i did mine.. pm me your info and ill find it and mail it out along with the instructions i used

Really nice of you etlsport, but I checked the exhaust and it seems fine, so I'd hate to take you up on your offer and not really need it
Thanks again though, I'll let you know in couple of weeks how the air pressure/gas tx experiment works (I alternate cars so it's not like I go a couple of weeks on one tank....)

[JHarris1385]

I would just check it anyways if I were you. I think it is one of the main contributing causes for bad mpg in the VX.

[Jolly Roger VX'er]

got 366.5 miles out of my last tank...low fuel light was on and the next gas station was like 15 miles away...so I didn't push it any further.

This was on mostly rural driving at a relaxed 50mph most of the time (speed limits on these types of roads are usually 45mph) with a little city and a very small amount of interstate driving.

I'd love to try for 400 miles if the right set of circumstances arises I think it's possible. I think 386 miles was possible on the last run as the low fuel light wasn't on all that long before I filled up. Figure I had like a couple gallons left which worst case should give me 30+ more miles.

I'm scared to run her out since I've heard of cases of burning up a fuel pump. I know I ran my fiero out one time and had to replace the pump not much later. I've only ran out of gas once in my life...lol.

[So-CalVX]

huh... I've run out of gas so many times before in previous vehicles and never had to change anything but my driving habit. :)
Is it really bad.

Actually, thinking about it now... My sister has run my old Ram out of gas atleast 4 times since she's had it and nothing...