FatGeek

Is it normal to run 4-5k rpms on the interstate? I bought the car for fuel economy, and on the interstate I keep wanting to upshift from 5th gear to bring the rpms down once up to 65-80mph.

When it comes time to replace the clutch, can the trans be modified to run lower rpms at higher speeds in 4th and 5th gear?

If vtec trans modification is blasphemy, forgive a fat old married guy who's used to driving a fullsize truck everywhere. Is 25mpg the best I'm going to get with 40+ miles of interstate driving daily?

94EG8

Yes.

You can replace 5th gear with one from an Integra LS tranny, it will lower your RPM somewhat.

Del Sol VTECs really weren't designed with mileage in mind. The B16 tranny is geared for all out acceleration above anything else. That said they do get half decent mileage for how high they rev. If its good fuel mileage you seek try to find a Civic VX hatchback and expect to double your mileage.

FatGeek

I lucked into getting the car, happened to be in the right place at the right time with enough cash on hand to buy it. Previous owner had wrecked it and I've put a new front end on it, had fun rebuilding it (only thing left is paint) and really enjoy driving it, but thought I would be tripling my gas mileage from my fullsize truck. Its still an improvement, just hate seeing 4500rpm @ 80mph, guess that's the price for being able to quickly accelerate in an unmodified car.

Thanks for the quick reply.

mattc28

i have a 92 civic ex with a d16 vtec and i get about 34mpg half backroads half highway..

FatGeek

matt, b16 here.

I think the VTEC is set to kick in around 5500rpm. Does that sound right for stock?

acake em1

yes it sounds right... i have a 99 si and i get 29mpg right now and i need to replace some stuff and my vtec kicks in at 5400

FatGeek

Cool. Thanks.

Lasky

look into an LS fifth gear.. rpms should be more around the 3500 range at 80 instead of 5000.. I have a B16 and had to get rid of my exhaust bc of all the highway driving i was doing.. quite annoying listening to a full exhaust at 5000 rpms for 30 minutes hahah

Lasky

i still get around 32 mpg tho

93HondaDelSolSi

i get around 28mpg combined with my Del Sol Si D16Z6. I sit a little over 3000rpm at 65, but I have 16" rims.

sde780

OP has a B16, not a D-series

RyanA

Yeah, high RPM's on the highway does suck if you have to do it for a few hours continuous. My wife got mid 30's with her 95 Del Sol VTEC. Even when I drove it and beat on it, the thing still got at least 27. We have pretty flat land around here so that makes the mileage better than many other places.

I do agree on the LS 5th. On a B16 trans, it will drop you from around 4000 rpm's at 70 to about 3200 or so.

FatGeek

Which exhaust did you go to? Phone calls at 4500 rpm are getting old.